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@@ -32,6 +32,8 @@
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<link rel="alternate" href="/ru/chapter_dynamic_programming/intro_to_dynamic_programming/" hreflang="ru">
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<link rel="alternate" href="/ko/chapter_dynamic_programming/intro_to_dynamic_programming/" hreflang="ko">
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<link rel="icon" href="../../assets/images/favicon.png">
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@@ -230,6 +232,12 @@
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</a>
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</li>
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<li class="md-select__item">
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<a href="/ko/chapter_dynamic_programming/intro_to_dynamic_programming/" hreflang="ko" class="md-select__link">
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한국어
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</a>
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</li>
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</ul>
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</div>
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</div>
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@@ -4711,7 +4719,7 @@
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<div class="tabbed-content">
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<div class="tabbed-block">
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<div class="highlight"><span class="filename">climbing_stairs_backtrack.py</span><pre><span></span><code><a id="__codelineno-0-1" name="__codelineno-0-1" href="#__codelineno-0-1"></a><span class="k">def</span><span class="w"> </span><span class="nf">backtrack</span><span class="p">(</span><span class="n">choices</span><span class="p">:</span> <span class="nb">list</span><span class="p">[</span><span class="nb">int</span><span class="p">],</span> <span class="n">state</span><span class="p">:</span> <span class="nb">int</span><span class="p">,</span> <span class="n">n</span><span class="p">:</span> <span class="nb">int</span><span class="p">,</span> <span class="n">res</span><span class="p">:</span> <span class="nb">list</span><span class="p">[</span><span class="nb">int</span><span class="p">])</span> <span class="o">-></span> <span class="nb">int</span><span class="p">:</span>
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<a id="__codelineno-0-2" name="__codelineno-0-2" href="#__codelineno-0-2"></a><span class="w"> </span><span class="sd">"""Бэктрекинг"""</span>
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<a id="__codelineno-0-2" name="__codelineno-0-2" href="#__codelineno-0-2"></a><span class="w"> </span><span class="sd">"""Бэктрекинг"""</span>
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<a id="__codelineno-0-3" name="__codelineno-0-3" href="#__codelineno-0-3"></a> <span class="c1"># Когда подъем достигает n-й ступени, число вариантов увеличивается на 1</span>
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<a id="__codelineno-0-4" name="__codelineno-0-4" href="#__codelineno-0-4"></a> <span class="k">if</span> <span class="n">state</span> <span class="o">==</span> <span class="n">n</span><span class="p">:</span>
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<a id="__codelineno-0-5" name="__codelineno-0-5" href="#__codelineno-0-5"></a> <span class="n">res</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="o">+=</span> <span class="mi">1</span>
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@@ -4725,7 +4733,7 @@
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<a id="__codelineno-0-13" name="__codelineno-0-13" href="#__codelineno-0-13"></a> <span class="c1"># Откат</span>
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<a id="__codelineno-0-14" name="__codelineno-0-14" href="#__codelineno-0-14"></a>
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<a id="__codelineno-0-15" name="__codelineno-0-15" href="#__codelineno-0-15"></a><span class="k">def</span><span class="w"> </span><span class="nf">climbing_stairs_backtrack</span><span class="p">(</span><span class="n">n</span><span class="p">:</span> <span class="nb">int</span><span class="p">)</span> <span class="o">-></span> <span class="nb">int</span><span class="p">:</span>
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<a id="__codelineno-0-16" name="__codelineno-0-16" href="#__codelineno-0-16"></a><span class="w"> </span><span class="sd">"""Подъем по лестнице: бэктрекинг"""</span>
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<a id="__codelineno-0-16" name="__codelineno-0-16" href="#__codelineno-0-16"></a><span class="w"> </span><span class="sd">"""Подъем по лестнице: бэктрекинг"""</span>
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<a id="__codelineno-0-17" name="__codelineno-0-17" href="#__codelineno-0-17"></a> <span class="n">choices</span> <span class="o">=</span> <span class="p">[</span><span class="mi">1</span><span class="p">,</span> <span class="mi">2</span><span class="p">]</span> <span class="c1"># Можно подняться на 1 или 2 ступени</span>
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<a id="__codelineno-0-18" name="__codelineno-0-18" href="#__codelineno-0-18"></a> <span class="n">state</span> <span class="o">=</span> <span class="mi">0</span> <span class="c1"># Начать подъем с 0-й ступени</span>
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<a id="__codelineno-0-19" name="__codelineno-0-19" href="#__codelineno-0-19"></a> <span class="n">res</span> <span class="o">=</span> <span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="c1"># Использовать res[0] для хранения числа решений</span>
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@@ -4820,12 +4828,12 @@
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<a id="__codelineno-4-2" name="__codelineno-4-2" href="#__codelineno-4-2"></a><span class="kd">func</span><span class="w"> </span><span class="nx">backtrack</span><span class="p">(</span><span class="nx">choices</span><span class="w"> </span><span class="p">[]</span><span class="kt">int</span><span class="p">,</span><span class="w"> </span><span class="nx">state</span><span class="p">,</span><span class="w"> </span><span class="nx">n</span><span class="w"> </span><span class="kt">int</span><span class="p">,</span><span class="w"> </span><span class="nx">res</span><span class="w"> </span><span class="p">[]</span><span class="kt">int</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
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<a id="__codelineno-4-3" name="__codelineno-4-3" href="#__codelineno-4-3"></a><span class="w"> </span><span class="c1">// Когда подъем достигает n-й ступени, число вариантов увеличивается на 1</span>
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<a id="__codelineno-4-4" name="__codelineno-4-4" href="#__codelineno-4-4"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">state</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="nx">n</span><span class="w"> </span><span class="p">{</span>
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<a id="__codelineno-4-5" name="__codelineno-4-5" href="#__codelineno-4-5"></a><span class="w"> </span><span class="nx">res</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nx">res</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">1</span>
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<a id="__codelineno-4-5" name="__codelineno-4-5" href="#__codelineno-4-5"></a><span class="w"> </span><span class="nx">res</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">res</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">1</span>
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<a id="__codelineno-4-6" name="__codelineno-4-6" href="#__codelineno-4-6"></a><span class="w"> </span><span class="p">}</span>
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<a id="__codelineno-4-7" name="__codelineno-4-7" href="#__codelineno-4-7"></a><span class="w"> </span><span class="c1">// Перебор всех вариантов выбора</span>
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<a id="__codelineno-4-8" name="__codelineno-4-8" href="#__codelineno-4-8"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="nx">_</span><span class="p">,</span><span class="w"> </span><span class="nx">choice</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="k">range</span><span class="w"> </span><span class="nx">choices</span><span class="w"> </span><span class="p">{</span>
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<a id="__codelineno-4-9" name="__codelineno-4-9" href="#__codelineno-4-9"></a><span class="w"> </span><span class="c1">// Отсечение: нельзя выходить за n-ю ступень</span>
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<a id="__codelineno-4-10" name="__codelineno-4-10" href="#__codelineno-4-10"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">state</span><span class="o">+</span><span class="nx">choice</span><span class="w"> </span><span class="p">></span><span class="w"> </span><span class="nx">n</span><span class="w"> </span><span class="p">{</span>
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<a id="__codelineno-4-10" name="__codelineno-4-10" href="#__codelineno-4-10"></a><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="nx">state</span><span class="o">+</span><span class="nx">choice</span><span class="w"> </span><span class="o">></span><span class="w"> </span><span class="nx">n</span><span class="w"> </span><span class="p">{</span>
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<a id="__codelineno-4-11" name="__codelineno-4-11" href="#__codelineno-4-11"></a><span class="w"> </span><span class="k">continue</span>
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<a id="__codelineno-4-12" name="__codelineno-4-12" href="#__codelineno-4-12"></a><span class="w"> </span><span class="p">}</span>
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<a id="__codelineno-4-13" name="__codelineno-4-13" href="#__codelineno-4-13"></a><span class="w"> </span><span class="c1">// Попытка: сделать выбор и обновить состояние</span>
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@@ -4842,7 +4850,7 @@
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<a id="__codelineno-4-24" name="__codelineno-4-24" href="#__codelineno-4-24"></a><span class="w"> </span><span class="nx">state</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="mi">0</span>
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<a id="__codelineno-4-25" name="__codelineno-4-25" href="#__codelineno-4-25"></a><span class="w"> </span><span class="nx">res</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nb">make</span><span class="p">([]</span><span class="kt">int</span><span class="p">,</span><span class="w"> </span><span class="mi">1</span><span class="p">)</span>
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<a id="__codelineno-4-26" name="__codelineno-4-26" href="#__codelineno-4-26"></a><span class="w"> </span><span class="c1">// Использовать res[0] для хранения числа решений</span>
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<a id="__codelineno-4-27" name="__codelineno-4-27" href="#__codelineno-4-27"></a><span class="w"> </span><span class="nx">res</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="mi">0</span>
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<a id="__codelineno-4-27" name="__codelineno-4-27" href="#__codelineno-4-27"></a><span class="w"> </span><span class="nx">res</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span>
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<a id="__codelineno-4-28" name="__codelineno-4-28" href="#__codelineno-4-28"></a><span class="w"> </span><span class="nx">backtrack</span><span class="p">(</span><span class="nx">choices</span><span class="p">,</span><span class="w"> </span><span class="nx">state</span><span class="p">,</span><span class="w"> </span><span class="nx">n</span><span class="p">,</span><span class="w"> </span><span class="nx">res</span><span class="p">)</span>
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<a id="__codelineno-4-29" name="__codelineno-4-29" href="#__codelineno-4-29"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">res</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span>
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<a id="__codelineno-4-30" name="__codelineno-4-30" href="#__codelineno-4-30"></a><span class="p">}</span>
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@@ -5087,7 +5095,7 @@
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</div>
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<details class="pythontutor">
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<summary>Визуализация кода</summary>
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<p><div style="height: 549px; width: 100%;"><iframe class="pythontutor-iframe" src="https://pythontutor.com/iframe-embed.html#code=def%20backtrack%28choices%3A%20list%5Bint%5D%2C%20state%3A%20int%2C%20n%3A%20int%2C%20res%3A%20list%5Bint%5D%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%91%D1%8D%D0%BA%D1%82%D1%80%D0%B5%D0%BA%D0%B8%D0%BD%D0%B3%22%22%22%0A%20%20%20%20%23%20%D0%9A%D0%BE%D0%B3%D0%B4%D0%B0%20%D0%BF%D0%BE%D0%B4%D1%8A%D0%B5%D0%BC%20%D0%B4%D0%BE%D1%81%D1%82%D0%B8%D0%B3%D0%B0%D0%B5%D1%82%20n-%D0%B9%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B8%2C%20%D1%87%D0%B8%D1%81%D0%BB%D0%BE%20%D0%B2%D0%B0%D1%80%D0%B8%D0%B0%D0%BD%D1%82%D0%BE%D0%B2%20%D1%83%D0%B2%D0%B5%D0%BB%D0%B8%D1%87%D0%B8%D0%B2%D0%B0%D0%B5%D1%82%D1%81%D1%8F%20%D0%BD%D0%B0%201%0A%20%20%20%20if%20state%20%3D%3D%20n%3A%0A%20%20%20%20%20%20%20%20res%5B0%5D%20%2B%3D%201%0A%20%20%20%20%23%20%D0%9F%D0%B5%D1%80%D0%B5%D0%B1%D0%BE%D1%80%20%D0%B2%D1%81%D0%B5%D1%85%20%D0%B2%D0%B0%D1%80%D0%B8%D0%B0%D0%BD%D1%82%D0%BE%D0%B2%20%D0%B2%D1%8B%D0%B1%D0%BE%D1%80%D0%B0%0A%20%20%20%20for%20choice%20in%20choices%3A%0A%20%20%20%20%20%20%20%20%23%20%D0%9E%D1%82%D1%81%D0%B5%D1%87%D0%B5%D0%BD%D0%B8%D0%B5%3A%20%D0%BD%D0%B5%D0%BB%D1%8C%D0%B7%D1%8F%20%D0%B2%D1%8B%D1%85%D0%BE%D0%B4%D0%B8%D1%82%D1%8C%20%D0%B7%D0%B0%20n-%D1%8E%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D1%8C%0A%20%20%20%20%20%20%20%20if%20state%20%2B%20choice%20%3E%20n%3A%0A%20%20%20%20%20%20%20%20%20%20%20%20continue%0A%20%20%20%20%20%20%20%20%23%20%D0%9F%D0%BE%D0%BF%D1%8B%D1%82%D0%BA%D0%B0%3A%20%D1%81%D0%B4%D0%B5%D0%BB%D0%B0%D1%82%D1%8C%20%D0%B2%D1%8B%D0%B1%D0%BE%D1%80%20%D0%B8%20%D0%BE%D0%B1%D0%BD%D0%BE%D0%B2%D0%B8%D1%82%D1%8C%20%D1%81%D0%BE%D1%81%D1%82%D0%BE%D1%8F%D0%BD%D0%B8%D0%B5%0A%20%20%20%20%20%20%20%20backtrack%28choices%2C%20state%20%2B%20choice%2C%20n%2C%20res%29%0A%20%20%20%20%20%20%20%20%23%20%D0%9E%D1%82%D0%BA%D0%B0%D1%82%0A%0A%0Adef%20climbing_stairs_backtrack%28n%3A%20int%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%9F%D0%BE%D0%B4%D1%8A%D0%B5%D0%BC%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%3A%20%D0%B1%D1%8D%D0%BA%D1%82%D1%80%D0%B5%D0%BA%D0%B8%D0%BD%D0%B3%22%22%22%0A%20%20%20%20choices%20%3D%20%5B1%2C%202%5D%20%20%23%20%D0%9C%D0%BE%D0%B6%D0%BD%D0%BE%20%D0%BF%D0%BE%D0%B4%D0%BD%D1%8F%D1%82%D1%8C%D1%81%D1%8F%20%D0%BD%D0%B0%201%20%D0%B8%D0%BB%D0%B8%202%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B8%0A%20%20%20%20state%20%3D%200%20%20%23%20%D0%9D%D0%B0%D1%87%D0%B0%D1%82%D1%8C%20%D0%BF%D0%BE%D0%B4%D1%8A%D0%B5%D0%BC%20%D1%81%200-%D0%B9%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B8%0A%20%20%20%20res%20%3D%20%5B0%5D%20%20%23%20%D0%98%D1%81%D0%BF%D0%BE%D0%BB%D1%8C%D0%B7%D0%BE%D0%B2%D0%B0%D1%82%D1%8C%20res%5B0%5D%20%D0%B4%D0%BB%D1%8F%20%D1%85%D1%80%D0%B0%D0%BD%D0%B5%D0%BD%D0%B8%D1%8F%20%D1%87%D0%B8%D1%81%D0%BB%D0%B0%20%D1%80%D0%B5%D1%88%D0%B5%D0%BD%D0%B8%D0%B9%0A%20%20%20%20backtrack%28choices%2C%20state%2C%20n%2C%20res%29%0A%20%20%20%20return%20res%5B0%5D%0A%0A%0A%22%22%22Driver%20Code%22%22%22%0Aif%20__name__%20%3D%3D%20%22__main__%22%3A%0A%20%20%20%20n%20%3D%204%0A%0A%20%20%20%20res%20%3D%20climbing_stairs_backtrack%28n%29%0A%20%20%20%20print%28f%22%D0%9A%D0%BE%D0%BB%D0%B8%D1%87%D0%B5%D1%81%D1%82%D0%B2%D0%BE%20%D1%81%D0%BF%D0%BE%D1%81%D0%BE%D0%B1%D0%BE%D0%B2%20%D0%BF%D0%BE%D0%B4%D0%BD%D1%8F%D1%82%D1%8C%D1%81%D1%8F%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%20%D0%B8%D0%B7%20%7Bn%7D%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B5%D0%B9%20%3D%20%7Bres%7D%22%29&codeDivHeight=472&codeDivWidth=350&cumulative=false&curInstr=5&heapPrimitives=nevernest&origin=opt-frontend.js&py=311&rawInputLstJSON=%5B%5D&textReferences=false"> </iframe></div>
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<p><div style="height: 549px; width: 100%;"><iframe class="pythontutor-iframe" title="Визуализация кода" src="https://pythontutor.com/iframe-embed.html#code=def%20backtrack%28choices%3A%20list%5Bint%5D%2C%20state%3A%20int%2C%20n%3A%20int%2C%20res%3A%20list%5Bint%5D%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%91%D1%8D%D0%BA%D1%82%D1%80%D0%B5%D0%BA%D0%B8%D0%BD%D0%B3%22%22%22%0A%20%20%20%20%23%20%D0%9A%D0%BE%D0%B3%D0%B4%D0%B0%20%D0%BF%D0%BE%D0%B4%D1%8A%D0%B5%D0%BC%20%D0%B4%D0%BE%D1%81%D1%82%D0%B8%D0%B3%D0%B0%D0%B5%D1%82%20n-%D0%B9%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B8%2C%20%D1%87%D0%B8%D1%81%D0%BB%D0%BE%20%D0%B2%D0%B0%D1%80%D0%B8%D0%B0%D0%BD%D1%82%D0%BE%D0%B2%20%D1%83%D0%B2%D0%B5%D0%BB%D0%B8%D1%87%D0%B8%D0%B2%D0%B0%D0%B5%D1%82%D1%81%D1%8F%20%D0%BD%D0%B0%201%0A%20%20%20%20if%20state%20%3D%3D%20n%3A%0A%20%20%20%20%20%20%20%20res%5B0%5D%20%2B%3D%201%0A%20%20%20%20%23%20%D0%9F%D0%B5%D1%80%D0%B5%D0%B1%D0%BE%D1%80%20%D0%B2%D1%81%D0%B5%D1%85%20%D0%B2%D0%B0%D1%80%D0%B8%D0%B0%D0%BD%D1%82%D0%BE%D0%B2%20%D0%B2%D1%8B%D0%B1%D0%BE%D1%80%D0%B0%0A%20%20%20%20for%20choice%20in%20choices%3A%0A%20%20%20%20%20%20%20%20%23%20%D0%9E%D1%82%D1%81%D0%B5%D1%87%D0%B5%D0%BD%D0%B8%D0%B5%3A%20%D0%BD%D0%B5%D0%BB%D1%8C%D0%B7%D1%8F%20%D0%B2%D1%8B%D1%85%D0%BE%D0%B4%D0%B8%D1%82%D1%8C%20%D0%B7%D0%B0%20n-%D1%8E%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D1%8C%0A%20%20%20%20%20%20%20%20if%20state%20%2B%20choice%20%3E%20n%3A%0A%20%20%20%20%20%20%20%20%20%20%20%20continue%0A%20%20%20%20%20%20%20%20%23%20%D0%9F%D0%BE%D0%BF%D1%8B%D1%82%D0%BA%D0%B0%3A%20%D1%81%D0%B4%D0%B5%D0%BB%D0%B0%D1%82%D1%8C%20%D0%B2%D1%8B%D0%B1%D0%BE%D1%80%20%D0%B8%20%D0%BE%D0%B1%D0%BD%D0%BE%D0%B2%D0%B8%D1%82%D1%8C%20%D1%81%D0%BE%D1%81%D1%82%D0%BE%D1%8F%D0%BD%D0%B8%D0%B5%0A%20%20%20%20%20%20%20%20backtrack%28choices%2C%20state%20%2B%20choice%2C%20n%2C%20res%29%0A%20%20%20%20%20%20%20%20%23%20%D0%9E%D1%82%D0%BA%D0%B0%D1%82%0A%0A%0Adef%20climbing_stairs_backtrack%28n%3A%20int%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%9F%D0%BE%D0%B4%D1%8A%D0%B5%D0%BC%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%3A%20%D0%B1%D1%8D%D0%BA%D1%82%D1%80%D0%B5%D0%BA%D0%B8%D0%BD%D0%B3%22%22%22%0A%20%20%20%20choices%20%3D%20%5B1%2C%202%5D%20%20%23%20%D0%9C%D0%BE%D0%B6%D0%BD%D0%BE%20%D0%BF%D0%BE%D0%B4%D0%BD%D1%8F%D1%82%D1%8C%D1%81%D1%8F%20%D0%BD%D0%B0%201%20%D0%B8%D0%BB%D0%B8%202%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B8%0A%20%20%20%20state%20%3D%200%20%20%23%20%D0%9D%D0%B0%D1%87%D0%B0%D1%82%D1%8C%20%D0%BF%D0%BE%D0%B4%D1%8A%D0%B5%D0%BC%20%D1%81%200-%D0%B9%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B8%0A%20%20%20%20res%20%3D%20%5B0%5D%20%20%23%20%D0%98%D1%81%D0%BF%D0%BE%D0%BB%D1%8C%D0%B7%D0%BE%D0%B2%D0%B0%D1%82%D1%8C%20res%5B0%5D%20%D0%B4%D0%BB%D1%8F%20%D1%85%D1%80%D0%B0%D0%BD%D0%B5%D0%BD%D0%B8%D1%8F%20%D1%87%D0%B8%D1%81%D0%BB%D0%B0%20%D1%80%D0%B5%D1%88%D0%B5%D0%BD%D0%B8%D0%B9%0A%20%20%20%20backtrack%28choices%2C%20state%2C%20n%2C%20res%29%0A%20%20%20%20return%20res%5B0%5D%0A%0A%0A%22%22%22Driver%20Code%22%22%22%0Aif%20__name__%20%3D%3D%20%22__main__%22%3A%0A%20%20%20%20n%20%3D%204%0A%0A%20%20%20%20res%20%3D%20climbing_stairs_backtrack%28n%29%0A%20%20%20%20print%28f%22%D0%9A%D0%BE%D0%BB%D0%B8%D1%87%D0%B5%D1%81%D1%82%D0%B2%D0%BE%20%D1%81%D0%BF%D0%BE%D1%81%D0%BE%D0%B1%D0%BE%D0%B2%20%D0%BF%D0%BE%D0%B4%D0%BD%D1%8F%D1%82%D1%8C%D1%81%D1%8F%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%20%D0%B8%D0%B7%20%7Bn%7D%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B5%D0%B9%20%3D%20%7Bres%7D%22%29&codeDivHeight=472&codeDivWidth=350&cumulative=false&curInstr=5&heapPrimitives=nevernest&origin=opt-frontend.js&py=311&rawInputLstJSON=%5B%5D&textReferences=false"> </iframe></div>
|
||||
<div style="margin-top: 5px;"><a href="https://pythontutor.com/iframe-embed.html#code=def%20backtrack%28choices%3A%20list%5Bint%5D%2C%20state%3A%20int%2C%20n%3A%20int%2C%20res%3A%20list%5Bint%5D%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%91%D1%8D%D0%BA%D1%82%D1%80%D0%B5%D0%BA%D0%B8%D0%BD%D0%B3%22%22%22%0A%20%20%20%20%23%20%D0%9A%D0%BE%D0%B3%D0%B4%D0%B0%20%D0%BF%D0%BE%D0%B4%D1%8A%D0%B5%D0%BC%20%D0%B4%D0%BE%D1%81%D1%82%D0%B8%D0%B3%D0%B0%D0%B5%D1%82%20n-%D0%B9%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B8%2C%20%D1%87%D0%B8%D1%81%D0%BB%D0%BE%20%D0%B2%D0%B0%D1%80%D0%B8%D0%B0%D0%BD%D1%82%D0%BE%D0%B2%20%D1%83%D0%B2%D0%B5%D0%BB%D0%B8%D1%87%D0%B8%D0%B2%D0%B0%D0%B5%D1%82%D1%81%D1%8F%20%D0%BD%D0%B0%201%0A%20%20%20%20if%20state%20%3D%3D%20n%3A%0A%20%20%20%20%20%20%20%20res%5B0%5D%20%2B%3D%201%0A%20%20%20%20%23%20%D0%9F%D0%B5%D1%80%D0%B5%D0%B1%D0%BE%D1%80%20%D0%B2%D1%81%D0%B5%D1%85%20%D0%B2%D0%B0%D1%80%D0%B8%D0%B0%D0%BD%D1%82%D0%BE%D0%B2%20%D0%B2%D1%8B%D0%B1%D0%BE%D1%80%D0%B0%0A%20%20%20%20for%20choice%20in%20choices%3A%0A%20%20%20%20%20%20%20%20%23%20%D0%9E%D1%82%D1%81%D0%B5%D1%87%D0%B5%D0%BD%D0%B8%D0%B5%3A%20%D0%BD%D0%B5%D0%BB%D1%8C%D0%B7%D1%8F%20%D0%B2%D1%8B%D1%85%D0%BE%D0%B4%D0%B8%D1%82%D1%8C%20%D0%B7%D0%B0%20n-%D1%8E%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D1%8C%0A%20%20%20%20%20%20%20%20if%20state%20%2B%20choice%20%3E%20n%3A%0A%20%20%20%20%20%20%20%20%20%20%20%20continue%0A%20%20%20%20%20%20%20%20%23%20%D0%9F%D0%BE%D0%BF%D1%8B%D1%82%D0%BA%D0%B0%3A%20%D1%81%D0%B4%D0%B5%D0%BB%D0%B0%D1%82%D1%8C%20%D0%B2%D1%8B%D0%B1%D0%BE%D1%80%20%D0%B8%20%D0%BE%D0%B1%D0%BD%D0%BE%D0%B2%D0%B8%D1%82%D1%8C%20%D1%81%D0%BE%D1%81%D1%82%D0%BE%D1%8F%D0%BD%D0%B8%D0%B5%0A%20%20%20%20%20%20%20%20backtrack%28choices%2C%20state%20%2B%20choice%2C%20n%2C%20res%29%0A%20%20%20%20%20%20%20%20%23%20%D0%9E%D1%82%D0%BA%D0%B0%D1%82%0A%0A%0Adef%20climbing_stairs_backtrack%28n%3A%20int%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%9F%D0%BE%D0%B4%D1%8A%D0%B5%D0%BC%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%3A%20%D0%B1%D1%8D%D0%BA%D1%82%D1%80%D0%B5%D0%BA%D0%B8%D0%BD%D0%B3%22%22%22%0A%20%20%20%20choices%20%3D%20%5B1%2C%202%5D%20%20%23%20%D0%9C%D0%BE%D0%B6%D0%BD%D0%BE%20%D0%BF%D0%BE%D0%B4%D0%BD%D1%8F%D1%82%D1%8C%D1%81%D1%8F%20%D0%BD%D0%B0%201%20%D0%B8%D0%BB%D0%B8%202%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B8%0A%20%20%20%20state%20%3D%200%20%20%23%20%D0%9D%D0%B0%D1%87%D0%B0%D1%82%D1%8C%20%D0%BF%D0%BE%D0%B4%D1%8A%D0%B5%D0%BC%20%D1%81%200-%D0%B9%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B8%0A%20%20%20%20res%20%3D%20%5B0%5D%20%20%23%20%D0%98%D1%81%D0%BF%D0%BE%D0%BB%D1%8C%D0%B7%D0%BE%D0%B2%D0%B0%D1%82%D1%8C%20res%5B0%5D%20%D0%B4%D0%BB%D1%8F%20%D1%85%D1%80%D0%B0%D0%BD%D0%B5%D0%BD%D0%B8%D1%8F%20%D1%87%D0%B8%D1%81%D0%BB%D0%B0%20%D1%80%D0%B5%D1%88%D0%B5%D0%BD%D0%B8%D0%B9%0A%20%20%20%20backtrack%28choices%2C%20state%2C%20n%2C%20res%29%0A%20%20%20%20return%20res%5B0%5D%0A%0A%0A%22%22%22Driver%20Code%22%22%22%0Aif%20__name__%20%3D%3D%20%22__main__%22%3A%0A%20%20%20%20n%20%3D%204%0A%0A%20%20%20%20res%20%3D%20climbing_stairs_backtrack%28n%29%0A%20%20%20%20print%28f%22%D0%9A%D0%BE%D0%BB%D0%B8%D1%87%D0%B5%D1%81%D1%82%D0%B2%D0%BE%20%D1%81%D0%BF%D0%BE%D1%81%D0%BE%D0%B1%D0%BE%D0%B2%20%D0%BF%D0%BE%D0%B4%D0%BD%D1%8F%D1%82%D1%8C%D1%81%D1%8F%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%20%D0%B8%D0%B7%20%7Bn%7D%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B5%D0%B9%20%3D%20%7Bres%7D%22%29&codeDivHeight=800&codeDivWidth=600&cumulative=false&curInstr=5&heapPrimitives=nevernest&origin=opt-frontend.js&py=311&rawInputLstJSON=%5B%5D&textReferences=false" target="_blank" rel="noopener noreferrer">Во весь экран ></a></div></p>
|
||||
</details>
|
||||
<h2 id="1411-1">14.1.1 Метод 1: полный перебор<a class="headerlink" href="#1411-1" title="Permanent link">¶</a></h2>
|
||||
@@ -5111,7 +5119,7 @@ dp[i] = dp[i-1] + dp[i-2]
|
||||
<div class="tabbed-content">
|
||||
<div class="tabbed-block">
|
||||
<div class="highlight"><span class="filename">climbing_stairs_dfs.py</span><pre><span></span><code><a id="__codelineno-13-1" name="__codelineno-13-1" href="#__codelineno-13-1"></a><span class="k">def</span><span class="w"> </span><span class="nf">dfs</span><span class="p">(</span><span class="n">i</span><span class="p">:</span> <span class="nb">int</span><span class="p">)</span> <span class="o">-></span> <span class="nb">int</span><span class="p">:</span>
|
||||
<a id="__codelineno-13-2" name="__codelineno-13-2" href="#__codelineno-13-2"></a><span class="w"> </span><span class="sd">"""Поиск"""</span>
|
||||
<a id="__codelineno-13-2" name="__codelineno-13-2" href="#__codelineno-13-2"></a><span class="w"> </span><span class="sd">"""Поиск"""</span>
|
||||
<a id="__codelineno-13-3" name="__codelineno-13-3" href="#__codelineno-13-3"></a> <span class="c1"># dp[1] и dp[2] уже известны, вернуть их</span>
|
||||
<a id="__codelineno-13-4" name="__codelineno-13-4" href="#__codelineno-13-4"></a> <span class="k">if</span> <span class="n">i</span> <span class="o">==</span> <span class="mi">1</span> <span class="ow">or</span> <span class="n">i</span> <span class="o">==</span> <span class="mi">2</span><span class="p">:</span>
|
||||
<a id="__codelineno-13-5" name="__codelineno-13-5" href="#__codelineno-13-5"></a> <span class="k">return</span> <span class="n">i</span>
|
||||
@@ -5120,7 +5128,7 @@ dp[i] = dp[i-1] + dp[i-2]
|
||||
<a id="__codelineno-13-8" name="__codelineno-13-8" href="#__codelineno-13-8"></a> <span class="k">return</span> <span class="n">count</span>
|
||||
<a id="__codelineno-13-9" name="__codelineno-13-9" href="#__codelineno-13-9"></a>
|
||||
<a id="__codelineno-13-10" name="__codelineno-13-10" href="#__codelineno-13-10"></a><span class="k">def</span><span class="w"> </span><span class="nf">climbing_stairs_dfs</span><span class="p">(</span><span class="n">n</span><span class="p">:</span> <span class="nb">int</span><span class="p">)</span> <span class="o">-></span> <span class="nb">int</span><span class="p">:</span>
|
||||
<a id="__codelineno-13-11" name="__codelineno-13-11" href="#__codelineno-13-11"></a><span class="w"> </span><span class="sd">"""Подъем по лестнице: поиск"""</span>
|
||||
<a id="__codelineno-13-11" name="__codelineno-13-11" href="#__codelineno-13-11"></a><span class="w"> </span><span class="sd">"""Подъем по лестнице: поиск"""</span>
|
||||
<a id="__codelineno-13-12" name="__codelineno-13-12" href="#__codelineno-13-12"></a> <span class="k">return</span> <span class="n">dfs</span><span class="p">(</span><span class="n">n</span><span class="p">)</span>
|
||||
</code></pre></div>
|
||||
</div>
|
||||
@@ -5329,7 +5337,7 @@ dp[i] = dp[i-1] + dp[i-2]
|
||||
</div>
|
||||
<details class="pythontutor">
|
||||
<summary>Визуализация кода</summary>
|
||||
<p><div style="height: 549px; width: 100%;"><iframe class="pythontutor-iframe" src="https://pythontutor.com/iframe-embed.html#code=def%20dfs%28i%3A%20int%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%9F%D0%BE%D0%B8%D1%81%D0%BA%22%22%22%0A%20%20%20%20%23%20dp%5B1%5D%20%D0%B8%20dp%5B2%5D%20%D1%83%D0%B6%D0%B5%20%D0%B8%D0%B7%D0%B2%D0%B5%D1%81%D1%82%D0%BD%D1%8B%2C%20%D0%B2%D0%B5%D1%80%D0%BD%D1%83%D1%82%D1%8C%20%D0%B8%D1%85%0A%20%20%20%20if%20i%20%3D%3D%201%20or%20i%20%3D%3D%202%3A%0A%20%20%20%20%20%20%20%20return%20i%0A%20%20%20%20%23%20dp%5Bi%5D%20%3D%20dp%5Bi-1%5D%20%2B%20dp%5Bi-2%5D%0A%20%20%20%20count%20%3D%20dfs%28i%20-%201%29%20%2B%20dfs%28i%20-%202%29%0A%20%20%20%20return%20count%0A%0A%0Adef%20climbing_stairs_dfs%28n%3A%20int%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%9F%D0%BE%D0%B4%D1%8A%D0%B5%D0%BC%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%3A%20%D0%BF%D0%BE%D0%B8%D1%81%D0%BA%22%22%22%0A%20%20%20%20return%20dfs%28n%29%0A%0A%0A%22%22%22Driver%20Code%22%22%22%0Aif%20__name__%20%3D%3D%20%22__main__%22%3A%0A%20%20%20%20n%20%3D%209%0A%0A%20%20%20%20res%20%3D%20climbing_stairs_dfs%28n%29%0A%20%20%20%20print%28f%22%D0%9A%D0%BE%D0%BB%D0%B8%D1%87%D0%B5%D1%81%D1%82%D0%B2%D0%BE%20%D1%81%D0%BF%D0%BE%D1%81%D0%BE%D0%B1%D0%BE%D0%B2%20%D0%BF%D0%BE%D0%B4%D0%BD%D1%8F%D1%82%D1%8C%D1%81%D1%8F%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%20%D0%B8%D0%B7%20%7Bn%7D%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B5%D0%B9%20%3D%20%7Bres%7D%22%29&codeDivHeight=472&codeDivWidth=350&cumulative=false&curInstr=5&heapPrimitives=nevernest&origin=opt-frontend.js&py=311&rawInputLstJSON=%5B%5D&textReferences=false"> </iframe></div>
|
||||
<p><div style="height: 549px; width: 100%;"><iframe class="pythontutor-iframe" title="Визуализация кода" src="https://pythontutor.com/iframe-embed.html#code=def%20dfs%28i%3A%20int%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%9F%D0%BE%D0%B8%D1%81%D0%BA%22%22%22%0A%20%20%20%20%23%20dp%5B1%5D%20%D0%B8%20dp%5B2%5D%20%D1%83%D0%B6%D0%B5%20%D0%B8%D0%B7%D0%B2%D0%B5%D1%81%D1%82%D0%BD%D1%8B%2C%20%D0%B2%D0%B5%D1%80%D0%BD%D1%83%D1%82%D1%8C%20%D0%B8%D1%85%0A%20%20%20%20if%20i%20%3D%3D%201%20or%20i%20%3D%3D%202%3A%0A%20%20%20%20%20%20%20%20return%20i%0A%20%20%20%20%23%20dp%5Bi%5D%20%3D%20dp%5Bi-1%5D%20%2B%20dp%5Bi-2%5D%0A%20%20%20%20count%20%3D%20dfs%28i%20-%201%29%20%2B%20dfs%28i%20-%202%29%0A%20%20%20%20return%20count%0A%0A%0Adef%20climbing_stairs_dfs%28n%3A%20int%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%9F%D0%BE%D0%B4%D1%8A%D0%B5%D0%BC%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%3A%20%D0%BF%D0%BE%D0%B8%D1%81%D0%BA%22%22%22%0A%20%20%20%20return%20dfs%28n%29%0A%0A%0A%22%22%22Driver%20Code%22%22%22%0Aif%20__name__%20%3D%3D%20%22__main__%22%3A%0A%20%20%20%20n%20%3D%209%0A%0A%20%20%20%20res%20%3D%20climbing_stairs_dfs%28n%29%0A%20%20%20%20print%28f%22%D0%9A%D0%BE%D0%BB%D0%B8%D1%87%D0%B5%D1%81%D1%82%D0%B2%D0%BE%20%D1%81%D0%BF%D0%BE%D1%81%D0%BE%D0%B1%D0%BE%D0%B2%20%D0%BF%D0%BE%D0%B4%D0%BD%D1%8F%D1%82%D1%8C%D1%81%D1%8F%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%20%D0%B8%D0%B7%20%7Bn%7D%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B5%D0%B9%20%3D%20%7Bres%7D%22%29&codeDivHeight=472&codeDivWidth=350&cumulative=false&curInstr=5&heapPrimitives=nevernest&origin=opt-frontend.js&py=311&rawInputLstJSON=%5B%5D&textReferences=false"> </iframe></div>
|
||||
<div style="margin-top: 5px;"><a href="https://pythontutor.com/iframe-embed.html#code=def%20dfs%28i%3A%20int%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%9F%D0%BE%D0%B8%D1%81%D0%BA%22%22%22%0A%20%20%20%20%23%20dp%5B1%5D%20%D0%B8%20dp%5B2%5D%20%D1%83%D0%B6%D0%B5%20%D0%B8%D0%B7%D0%B2%D0%B5%D1%81%D1%82%D0%BD%D1%8B%2C%20%D0%B2%D0%B5%D1%80%D0%BD%D1%83%D1%82%D1%8C%20%D0%B8%D1%85%0A%20%20%20%20if%20i%20%3D%3D%201%20or%20i%20%3D%3D%202%3A%0A%20%20%20%20%20%20%20%20return%20i%0A%20%20%20%20%23%20dp%5Bi%5D%20%3D%20dp%5Bi-1%5D%20%2B%20dp%5Bi-2%5D%0A%20%20%20%20count%20%3D%20dfs%28i%20-%201%29%20%2B%20dfs%28i%20-%202%29%0A%20%20%20%20return%20count%0A%0A%0Adef%20climbing_stairs_dfs%28n%3A%20int%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%9F%D0%BE%D0%B4%D1%8A%D0%B5%D0%BC%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%3A%20%D0%BF%D0%BE%D0%B8%D1%81%D0%BA%22%22%22%0A%20%20%20%20return%20dfs%28n%29%0A%0A%0A%22%22%22Driver%20Code%22%22%22%0Aif%20__name__%20%3D%3D%20%22__main__%22%3A%0A%20%20%20%20n%20%3D%209%0A%0A%20%20%20%20res%20%3D%20climbing_stairs_dfs%28n%29%0A%20%20%20%20print%28f%22%D0%9A%D0%BE%D0%BB%D0%B8%D1%87%D0%B5%D1%81%D1%82%D0%B2%D0%BE%20%D1%81%D0%BF%D0%BE%D1%81%D0%BE%D0%B1%D0%BE%D0%B2%20%D0%BF%D0%BE%D0%B4%D0%BD%D1%8F%D1%82%D1%8C%D1%81%D1%8F%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%20%D0%B8%D0%B7%20%7Bn%7D%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B5%D0%B9%20%3D%20%7Bres%7D%22%29&codeDivHeight=800&codeDivWidth=600&cumulative=false&curInstr=5&heapPrimitives=nevernest&origin=opt-frontend.js&py=311&rawInputLstJSON=%5B%5D&textReferences=false" target="_blank" rel="noopener noreferrer">Во весь экран ></a></div></p>
|
||||
</details>
|
||||
<p>На рисунке 14-3 показано дерево рекурсии, возникающее при полном переборе. Для задачи <span class="arithmatex">\(dp[n]\)</span> глубина дерева рекурсии равна <span class="arithmatex">\(n\)</span> , а временная сложность равна <span class="arithmatex">\(O(2^n)\)</span> . Экспоненциальный рост взрывообразен: если подать на вход достаточно большое значение <span class="arithmatex">\(n\)</span> , ожидание станет очень долгим.</p>
|
||||
@@ -5349,7 +5357,7 @@ dp[i] = dp[i-1] + dp[i-2]
|
||||
<div class="tabbed-content">
|
||||
<div class="tabbed-block">
|
||||
<div class="highlight"><span class="filename">climbing_stairs_dfs_mem.py</span><pre><span></span><code><a id="__codelineno-26-1" name="__codelineno-26-1" href="#__codelineno-26-1"></a><span class="k">def</span><span class="w"> </span><span class="nf">dfs</span><span class="p">(</span><span class="n">i</span><span class="p">:</span> <span class="nb">int</span><span class="p">,</span> <span class="n">mem</span><span class="p">:</span> <span class="nb">list</span><span class="p">[</span><span class="nb">int</span><span class="p">])</span> <span class="o">-></span> <span class="nb">int</span><span class="p">:</span>
|
||||
<a id="__codelineno-26-2" name="__codelineno-26-2" href="#__codelineno-26-2"></a><span class="w"> </span><span class="sd">"""Поиск с мемоизацией"""</span>
|
||||
<a id="__codelineno-26-2" name="__codelineno-26-2" href="#__codelineno-26-2"></a><span class="w"> </span><span class="sd">"""Поиск с мемоизацией"""</span>
|
||||
<a id="__codelineno-26-3" name="__codelineno-26-3" href="#__codelineno-26-3"></a> <span class="c1"># dp[1] и dp[2] уже известны, вернуть их</span>
|
||||
<a id="__codelineno-26-4" name="__codelineno-26-4" href="#__codelineno-26-4"></a> <span class="k">if</span> <span class="n">i</span> <span class="o">==</span> <span class="mi">1</span> <span class="ow">or</span> <span class="n">i</span> <span class="o">==</span> <span class="mi">2</span><span class="p">:</span>
|
||||
<a id="__codelineno-26-5" name="__codelineno-26-5" href="#__codelineno-26-5"></a> <span class="k">return</span> <span class="n">i</span>
|
||||
@@ -5363,7 +5371,7 @@ dp[i] = dp[i-1] + dp[i-2]
|
||||
<a id="__codelineno-26-13" name="__codelineno-26-13" href="#__codelineno-26-13"></a> <span class="k">return</span> <span class="n">count</span>
|
||||
<a id="__codelineno-26-14" name="__codelineno-26-14" href="#__codelineno-26-14"></a>
|
||||
<a id="__codelineno-26-15" name="__codelineno-26-15" href="#__codelineno-26-15"></a><span class="k">def</span><span class="w"> </span><span class="nf">climbing_stairs_dfs_mem</span><span class="p">(</span><span class="n">n</span><span class="p">:</span> <span class="nb">int</span><span class="p">)</span> <span class="o">-></span> <span class="nb">int</span><span class="p">:</span>
|
||||
<a id="__codelineno-26-16" name="__codelineno-26-16" href="#__codelineno-26-16"></a><span class="w"> </span><span class="sd">"""Подъем по лестнице: поиск с мемоизацией"""</span>
|
||||
<a id="__codelineno-26-16" name="__codelineno-26-16" href="#__codelineno-26-16"></a><span class="w"> </span><span class="sd">"""Подъем по лестнице: поиск с мемоизацией"""</span>
|
||||
<a id="__codelineno-26-17" name="__codelineno-26-17" href="#__codelineno-26-17"></a> <span class="c1"># mem[i] хранит число способов подняться на i-ю ступень, -1 означает отсутствие записи</span>
|
||||
<a id="__codelineno-26-18" name="__codelineno-26-18" href="#__codelineno-26-18"></a> <span class="n">mem</span> <span class="o">=</span> <span class="p">[</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span> <span class="o">*</span> <span class="p">(</span><span class="n">n</span> <span class="o">+</span> <span class="mi">1</span><span class="p">)</span>
|
||||
<a id="__codelineno-26-19" name="__codelineno-26-19" href="#__codelineno-26-19"></a> <span class="k">return</span> <span class="n">dfs</span><span class="p">(</span><span class="n">n</span><span class="p">,</span> <span class="n">mem</span><span class="p">)</span>
|
||||
@@ -5457,7 +5465,7 @@ dp[i] = dp[i-1] + dp[i-2]
|
||||
<a id="__codelineno-30-11" name="__codelineno-30-11" href="#__codelineno-30-11"></a><span class="w"> </span><span class="c1">// dp[i] = dp[i-1] + dp[i-2]</span>
|
||||
<a id="__codelineno-30-12" name="__codelineno-30-12" href="#__codelineno-30-12"></a><span class="w"> </span><span class="nx">count</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nx">dfsMem</span><span class="p">(</span><span class="nx">i</span><span class="o">-</span><span class="mi">1</span><span class="p">,</span><span class="w"> </span><span class="nx">mem</span><span class="p">)</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">dfsMem</span><span class="p">(</span><span class="nx">i</span><span class="o">-</span><span class="mi">2</span><span class="p">,</span><span class="w"> </span><span class="nx">mem</span><span class="p">)</span>
|
||||
<a id="__codelineno-30-13" name="__codelineno-30-13" href="#__codelineno-30-13"></a><span class="w"> </span><span class="c1">// Сохранить dp[i]</span>
|
||||
<a id="__codelineno-30-14" name="__codelineno-30-14" href="#__codelineno-30-14"></a><span class="w"> </span><span class="nx">mem</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nx">count</span>
|
||||
<a id="__codelineno-30-14" name="__codelineno-30-14" href="#__codelineno-30-14"></a><span class="w"> </span><span class="nx">mem</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">count</span>
|
||||
<a id="__codelineno-30-15" name="__codelineno-30-15" href="#__codelineno-30-15"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">count</span>
|
||||
<a id="__codelineno-30-16" name="__codelineno-30-16" href="#__codelineno-30-16"></a><span class="p">}</span>
|
||||
<a id="__codelineno-30-17" name="__codelineno-30-17" href="#__codelineno-30-17"></a>
|
||||
@@ -5466,7 +5474,7 @@ dp[i] = dp[i-1] + dp[i-2]
|
||||
<a id="__codelineno-30-20" name="__codelineno-30-20" href="#__codelineno-30-20"></a><span class="w"> </span><span class="c1">// mem[i] хранит число способов подняться на i-ю ступень, -1 означает отсутствие записи</span>
|
||||
<a id="__codelineno-30-21" name="__codelineno-30-21" href="#__codelineno-30-21"></a><span class="w"> </span><span class="nx">mem</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nb">make</span><span class="p">([]</span><span class="kt">int</span><span class="p">,</span><span class="w"> </span><span class="nx">n</span><span class="o">+</span><span class="mi">1</span><span class="p">)</span>
|
||||
<a id="__codelineno-30-22" name="__codelineno-30-22" href="#__codelineno-30-22"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="k">range</span><span class="w"> </span><span class="nx">mem</span><span class="w"> </span><span class="p">{</span>
|
||||
<a id="__codelineno-30-23" name="__codelineno-30-23" href="#__codelineno-30-23"></a><span class="w"> </span><span class="nx">mem</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="o">-</span><span class="mi">1</span>
|
||||
<a id="__codelineno-30-23" name="__codelineno-30-23" href="#__codelineno-30-23"></a><span class="w"> </span><span class="nx">mem</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="o">-</span><span class="mi">1</span>
|
||||
<a id="__codelineno-30-24" name="__codelineno-30-24" href="#__codelineno-30-24"></a><span class="w"> </span><span class="p">}</span>
|
||||
<a id="__codelineno-30-25" name="__codelineno-30-25" href="#__codelineno-30-25"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">dfsMem</span><span class="p">(</span><span class="nx">n</span><span class="p">,</span><span class="w"> </span><span class="nx">mem</span><span class="p">)</span>
|
||||
<a id="__codelineno-30-26" name="__codelineno-30-26" href="#__codelineno-30-26"></a><span class="p">}</span>
|
||||
@@ -5668,7 +5676,7 @@ dp[i] = dp[i-1] + dp[i-2]
|
||||
</div>
|
||||
<details class="pythontutor">
|
||||
<summary>Визуализация кода</summary>
|
||||
<p><div style="height: 549px; width: 100%;"><iframe class="pythontutor-iframe" src="https://pythontutor.com/iframe-embed.html#code=def%20dfs%28i%3A%20int%2C%20mem%3A%20list%5Bint%5D%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%9F%D0%BE%D0%B8%D1%81%D0%BA%20%D1%81%20%D0%BC%D0%B5%D0%BC%D0%BE%D0%B8%D0%B7%D0%B0%D1%86%D0%B8%D0%B5%D0%B9%22%22%22%0A%20%20%20%20%23%20dp%5B1%5D%20%D0%B8%20dp%5B2%5D%20%D1%83%D0%B6%D0%B5%20%D0%B8%D0%B7%D0%B2%D0%B5%D1%81%D1%82%D0%BD%D1%8B%2C%20%D0%B2%D0%B5%D1%80%D0%BD%D1%83%D1%82%D1%8C%20%D0%B8%D1%85%0A%20%20%20%20if%20i%20%3D%3D%201%20or%20i%20%3D%3D%202%3A%0A%20%20%20%20%20%20%20%20return%20i%0A%20%20%20%20%23%20%D0%95%D1%81%D0%BB%D0%B8%20%D0%B7%D0%B0%D0%BF%D0%B8%D1%81%D1%8C%20dp%5Bi%5D%20%D1%81%D1%83%D1%89%D0%B5%D1%81%D1%82%D0%B2%D1%83%D0%B5%D1%82%2C%20%D1%81%D1%80%D0%B0%D0%B7%D1%83%20%D0%B2%D0%B5%D1%80%D0%BD%D1%83%D1%82%D1%8C%20%D0%B5%D0%B5%0A%20%20%20%20if%20mem%5Bi%5D%20%21%3D%20-1%3A%0A%20%20%20%20%20%20%20%20return%20mem%5Bi%5D%0A%20%20%20%20%23%20dp%5Bi%5D%20%3D%20dp%5Bi-1%5D%20%2B%20dp%5Bi-2%5D%0A%20%20%20%20count%20%3D%20dfs%28i%20-%201%2C%20mem%29%20%2B%20dfs%28i%20-%202%2C%20mem%29%0A%20%20%20%20%23%20%D0%A1%D0%BE%D1%85%D1%80%D0%B0%D0%BD%D0%B8%D1%82%D1%8C%20dp%5Bi%5D%0A%20%20%20%20mem%5Bi%5D%20%3D%20count%0A%20%20%20%20return%20count%0A%0A%0Adef%20climbing_stairs_dfs_mem%28n%3A%20int%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%9F%D0%BE%D0%B4%D1%8A%D0%B5%D0%BC%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%3A%20%D0%BF%D0%BE%D0%B8%D1%81%D0%BA%20%D1%81%20%D0%BC%D0%B5%D0%BC%D0%BE%D0%B8%D0%B7%D0%B0%D1%86%D0%B8%D0%B5%D0%B9%22%22%22%0A%20%20%20%20%23%20mem%5Bi%5D%20%D1%85%D1%80%D0%B0%D0%BD%D0%B8%D1%82%20%D1%87%D0%B8%D1%81%D0%BB%D0%BE%20%D1%81%D0%BF%D0%BE%D1%81%D0%BE%D0%B1%D0%BE%D0%B2%20%D0%BF%D0%BE%D0%B4%D0%BD%D1%8F%D1%82%D1%8C%D1%81%D1%8F%20%D0%BD%D0%B0%20i-%D1%8E%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D1%8C%2C%20-1%20%D0%BE%D0%B7%D0%BD%D0%B0%D1%87%D0%B0%D0%B5%D1%82%20%D0%BE%D1%82%D1%81%D1%83%D1%82%D1%81%D1%82%D0%B2%D0%B8%D0%B5%20%D0%B7%D0%B0%D0%BF%D0%B8%D1%81%D0%B8%0A%20%20%20%20mem%20%3D%20%5B-1%5D%20%2A%20%28n%20%2B%201%29%0A%20%20%20%20return%20dfs%28n%2C%20mem%29%0A%0A%0A%22%22%22Driver%20Code%22%22%22%0Aif%20__name__%20%3D%3D%20%22__main__%22%3A%0A%20%20%20%20n%20%3D%209%0A%0A%20%20%20%20res%20%3D%20climbing_stairs_dfs_mem%28n%29%0A%20%20%20%20print%28f%22%D0%9A%D0%BE%D0%BB%D0%B8%D1%87%D0%B5%D1%81%D1%82%D0%B2%D0%BE%20%D1%81%D0%BF%D0%BE%D1%81%D0%BE%D0%B1%D0%BE%D0%B2%20%D0%BF%D0%BE%D0%B4%D0%BD%D1%8F%D1%82%D1%8C%D1%81%D1%8F%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%20%D0%B8%D0%B7%20%7Bn%7D%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B5%D0%B9%20%3D%20%7Bres%7D%22%29&codeDivHeight=472&codeDivWidth=350&cumulative=false&curInstr=5&heapPrimitives=nevernest&origin=opt-frontend.js&py=311&rawInputLstJSON=%5B%5D&textReferences=false"> </iframe></div>
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<p><div style="height: 549px; width: 100%;"><iframe class="pythontutor-iframe" title="Визуализация кода" src="https://pythontutor.com/iframe-embed.html#code=def%20dfs%28i%3A%20int%2C%20mem%3A%20list%5Bint%5D%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%9F%D0%BE%D0%B8%D1%81%D0%BA%20%D1%81%20%D0%BC%D0%B5%D0%BC%D0%BE%D0%B8%D0%B7%D0%B0%D1%86%D0%B8%D0%B5%D0%B9%22%22%22%0A%20%20%20%20%23%20dp%5B1%5D%20%D0%B8%20dp%5B2%5D%20%D1%83%D0%B6%D0%B5%20%D0%B8%D0%B7%D0%B2%D0%B5%D1%81%D1%82%D0%BD%D1%8B%2C%20%D0%B2%D0%B5%D1%80%D0%BD%D1%83%D1%82%D1%8C%20%D0%B8%D1%85%0A%20%20%20%20if%20i%20%3D%3D%201%20or%20i%20%3D%3D%202%3A%0A%20%20%20%20%20%20%20%20return%20i%0A%20%20%20%20%23%20%D0%95%D1%81%D0%BB%D0%B8%20%D0%B7%D0%B0%D0%BF%D0%B8%D1%81%D1%8C%20dp%5Bi%5D%20%D1%81%D1%83%D1%89%D0%B5%D1%81%D1%82%D0%B2%D1%83%D0%B5%D1%82%2C%20%D1%81%D1%80%D0%B0%D0%B7%D1%83%20%D0%B2%D0%B5%D1%80%D0%BD%D1%83%D1%82%D1%8C%20%D0%B5%D0%B5%0A%20%20%20%20if%20mem%5Bi%5D%20%21%3D%20-1%3A%0A%20%20%20%20%20%20%20%20return%20mem%5Bi%5D%0A%20%20%20%20%23%20dp%5Bi%5D%20%3D%20dp%5Bi-1%5D%20%2B%20dp%5Bi-2%5D%0A%20%20%20%20count%20%3D%20dfs%28i%20-%201%2C%20mem%29%20%2B%20dfs%28i%20-%202%2C%20mem%29%0A%20%20%20%20%23%20%D0%A1%D0%BE%D1%85%D1%80%D0%B0%D0%BD%D0%B8%D1%82%D1%8C%20dp%5Bi%5D%0A%20%20%20%20mem%5Bi%5D%20%3D%20count%0A%20%20%20%20return%20count%0A%0A%0Adef%20climbing_stairs_dfs_mem%28n%3A%20int%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%9F%D0%BE%D0%B4%D1%8A%D0%B5%D0%BC%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%3A%20%D0%BF%D0%BE%D0%B8%D1%81%D0%BA%20%D1%81%20%D0%BC%D0%B5%D0%BC%D0%BE%D0%B8%D0%B7%D0%B0%D1%86%D0%B8%D0%B5%D0%B9%22%22%22%0A%20%20%20%20%23%20mem%5Bi%5D%20%D1%85%D1%80%D0%B0%D0%BD%D0%B8%D1%82%20%D1%87%D0%B8%D1%81%D0%BB%D0%BE%20%D1%81%D0%BF%D0%BE%D1%81%D0%BE%D0%B1%D0%BE%D0%B2%20%D0%BF%D0%BE%D0%B4%D0%BD%D1%8F%D1%82%D1%8C%D1%81%D1%8F%20%D0%BD%D0%B0%20i-%D1%8E%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D1%8C%2C%20-1%20%D0%BE%D0%B7%D0%BD%D0%B0%D1%87%D0%B0%D0%B5%D1%82%20%D0%BE%D1%82%D1%81%D1%83%D1%82%D1%81%D1%82%D0%B2%D0%B8%D0%B5%20%D0%B7%D0%B0%D0%BF%D0%B8%D1%81%D0%B8%0A%20%20%20%20mem%20%3D%20%5B-1%5D%20%2A%20%28n%20%2B%201%29%0A%20%20%20%20return%20dfs%28n%2C%20mem%29%0A%0A%0A%22%22%22Driver%20Code%22%22%22%0Aif%20__name__%20%3D%3D%20%22__main__%22%3A%0A%20%20%20%20n%20%3D%209%0A%0A%20%20%20%20res%20%3D%20climbing_stairs_dfs_mem%28n%29%0A%20%20%20%20print%28f%22%D0%9A%D0%BE%D0%BB%D0%B8%D1%87%D0%B5%D1%81%D1%82%D0%B2%D0%BE%20%D1%81%D0%BF%D0%BE%D1%81%D0%BE%D0%B1%D0%BE%D0%B2%20%D0%BF%D0%BE%D0%B4%D0%BD%D1%8F%D1%82%D1%8C%D1%81%D1%8F%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%20%D0%B8%D0%B7%20%7Bn%7D%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B5%D0%B9%20%3D%20%7Bres%7D%22%29&codeDivHeight=472&codeDivWidth=350&cumulative=false&curInstr=5&heapPrimitives=nevernest&origin=opt-frontend.js&py=311&rawInputLstJSON=%5B%5D&textReferences=false"> </iframe></div>
|
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<div style="margin-top: 5px;"><a href="https://pythontutor.com/iframe-embed.html#code=def%20dfs%28i%3A%20int%2C%20mem%3A%20list%5Bint%5D%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%9F%D0%BE%D0%B8%D1%81%D0%BA%20%D1%81%20%D0%BC%D0%B5%D0%BC%D0%BE%D0%B8%D0%B7%D0%B0%D1%86%D0%B8%D0%B5%D0%B9%22%22%22%0A%20%20%20%20%23%20dp%5B1%5D%20%D0%B8%20dp%5B2%5D%20%D1%83%D0%B6%D0%B5%20%D0%B8%D0%B7%D0%B2%D0%B5%D1%81%D1%82%D0%BD%D1%8B%2C%20%D0%B2%D0%B5%D1%80%D0%BD%D1%83%D1%82%D1%8C%20%D0%B8%D1%85%0A%20%20%20%20if%20i%20%3D%3D%201%20or%20i%20%3D%3D%202%3A%0A%20%20%20%20%20%20%20%20return%20i%0A%20%20%20%20%23%20%D0%95%D1%81%D0%BB%D0%B8%20%D0%B7%D0%B0%D0%BF%D0%B8%D1%81%D1%8C%20dp%5Bi%5D%20%D1%81%D1%83%D1%89%D0%B5%D1%81%D1%82%D0%B2%D1%83%D0%B5%D1%82%2C%20%D1%81%D1%80%D0%B0%D0%B7%D1%83%20%D0%B2%D0%B5%D1%80%D0%BD%D1%83%D1%82%D1%8C%20%D0%B5%D0%B5%0A%20%20%20%20if%20mem%5Bi%5D%20%21%3D%20-1%3A%0A%20%20%20%20%20%20%20%20return%20mem%5Bi%5D%0A%20%20%20%20%23%20dp%5Bi%5D%20%3D%20dp%5Bi-1%5D%20%2B%20dp%5Bi-2%5D%0A%20%20%20%20count%20%3D%20dfs%28i%20-%201%2C%20mem%29%20%2B%20dfs%28i%20-%202%2C%20mem%29%0A%20%20%20%20%23%20%D0%A1%D0%BE%D1%85%D1%80%D0%B0%D0%BD%D0%B8%D1%82%D1%8C%20dp%5Bi%5D%0A%20%20%20%20mem%5Bi%5D%20%3D%20count%0A%20%20%20%20return%20count%0A%0A%0Adef%20climbing_stairs_dfs_mem%28n%3A%20int%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%9F%D0%BE%D0%B4%D1%8A%D0%B5%D0%BC%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%3A%20%D0%BF%D0%BE%D0%B8%D1%81%D0%BA%20%D1%81%20%D0%BC%D0%B5%D0%BC%D0%BE%D0%B8%D0%B7%D0%B0%D1%86%D0%B8%D0%B5%D0%B9%22%22%22%0A%20%20%20%20%23%20mem%5Bi%5D%20%D1%85%D1%80%D0%B0%D0%BD%D0%B8%D1%82%20%D1%87%D0%B8%D1%81%D0%BB%D0%BE%20%D1%81%D0%BF%D0%BE%D1%81%D0%BE%D0%B1%D0%BE%D0%B2%20%D0%BF%D0%BE%D0%B4%D0%BD%D1%8F%D1%82%D1%8C%D1%81%D1%8F%20%D0%BD%D0%B0%20i-%D1%8E%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D1%8C%2C%20-1%20%D0%BE%D0%B7%D0%BD%D0%B0%D1%87%D0%B0%D0%B5%D1%82%20%D0%BE%D1%82%D1%81%D1%83%D1%82%D1%81%D1%82%D0%B2%D0%B8%D0%B5%20%D0%B7%D0%B0%D0%BF%D0%B8%D1%81%D0%B8%0A%20%20%20%20mem%20%3D%20%5B-1%5D%20%2A%20%28n%20%2B%201%29%0A%20%20%20%20return%20dfs%28n%2C%20mem%29%0A%0A%0A%22%22%22Driver%20Code%22%22%22%0Aif%20__name__%20%3D%3D%20%22__main__%22%3A%0A%20%20%20%20n%20%3D%209%0A%0A%20%20%20%20res%20%3D%20climbing_stairs_dfs_mem%28n%29%0A%20%20%20%20print%28f%22%D0%9A%D0%BE%D0%BB%D0%B8%D1%87%D0%B5%D1%81%D1%82%D0%B2%D0%BE%20%D1%81%D0%BF%D0%BE%D1%81%D0%BE%D0%B1%D0%BE%D0%B2%20%D0%BF%D0%BE%D0%B4%D0%BD%D1%8F%D1%82%D1%8C%D1%81%D1%8F%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%20%D0%B8%D0%B7%20%7Bn%7D%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B5%D0%B9%20%3D%20%7Bres%7D%22%29&codeDivHeight=800&codeDivWidth=600&cumulative=false&curInstr=5&heapPrimitives=nevernest&origin=opt-frontend.js&py=311&rawInputLstJSON=%5B%5D&textReferences=false" target="_blank" rel="noopener noreferrer">Во весь экран ></a></div></p>
|
||||
</details>
|
||||
<p>Как показано на рисунке 14-4, <strong>после введения мемоизации каждая перекрывающаяся подзадача вычисляется только один раз, и временная сложность оптимизируется до <span class="arithmatex">\(O(n)\)</span></strong> . Это огромный скачок в эффективности.</p>
|
||||
@@ -5683,7 +5691,7 @@ dp[i] = dp[i-1] + dp[i-2]
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<div class="tabbed-content">
|
||||
<div class="tabbed-block">
|
||||
<div class="highlight"><span class="filename">climbing_stairs_dp.py</span><pre><span></span><code><a id="__codelineno-39-1" name="__codelineno-39-1" href="#__codelineno-39-1"></a><span class="k">def</span><span class="w"> </span><span class="nf">climbing_stairs_dp</span><span class="p">(</span><span class="n">n</span><span class="p">:</span> <span class="nb">int</span><span class="p">)</span> <span class="o">-></span> <span class="nb">int</span><span class="p">:</span>
|
||||
<a id="__codelineno-39-2" name="__codelineno-39-2" href="#__codelineno-39-2"></a><span class="w"> </span><span class="sd">"""Подъем по лестнице: динамическое программирование"""</span>
|
||||
<a id="__codelineno-39-2" name="__codelineno-39-2" href="#__codelineno-39-2"></a><span class="w"> </span><span class="sd">"""Подъем по лестнице: динамическое программирование"""</span>
|
||||
<a id="__codelineno-39-3" name="__codelineno-39-3" href="#__codelineno-39-3"></a> <span class="k">if</span> <span class="n">n</span> <span class="o">==</span> <span class="mi">1</span> <span class="ow">or</span> <span class="n">n</span> <span class="o">==</span> <span class="mi">2</span><span class="p">:</span>
|
||||
<a id="__codelineno-39-4" name="__codelineno-39-4" href="#__codelineno-39-4"></a> <span class="k">return</span> <span class="n">n</span>
|
||||
<a id="__codelineno-39-5" name="__codelineno-39-5" href="#__codelineno-39-5"></a> <span class="c1"># Инициализация таблицы dp для хранения решений подзадач</span>
|
||||
@@ -5759,11 +5767,11 @@ dp[i] = dp[i-1] + dp[i-2]
|
||||
<a id="__codelineno-43-6" name="__codelineno-43-6" href="#__codelineno-43-6"></a><span class="w"> </span><span class="c1">// Инициализация таблицы dp для хранения решений подзадач</span>
|
||||
<a id="__codelineno-43-7" name="__codelineno-43-7" href="#__codelineno-43-7"></a><span class="w"> </span><span class="nx">dp</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="nb">make</span><span class="p">([]</span><span class="kt">int</span><span class="p">,</span><span class="w"> </span><span class="nx">n</span><span class="o">+</span><span class="mi">1</span><span class="p">)</span>
|
||||
<a id="__codelineno-43-8" name="__codelineno-43-8" href="#__codelineno-43-8"></a><span class="w"> </span><span class="c1">// Начальное состояние: заранее задать решения наименьших подзадач</span>
|
||||
<a id="__codelineno-43-9" name="__codelineno-43-9" href="#__codelineno-43-9"></a><span class="w"> </span><span class="nx">dp</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="mi">1</span>
|
||||
<a id="__codelineno-43-10" name="__codelineno-43-10" href="#__codelineno-43-10"></a><span class="w"> </span><span class="nx">dp</span><span class="p">[</span><span class="mi">2</span><span class="p">]</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="mi">2</span>
|
||||
<a id="__codelineno-43-9" name="__codelineno-43-9" href="#__codelineno-43-9"></a><span class="w"> </span><span class="nx">dp</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">1</span>
|
||||
<a id="__codelineno-43-10" name="__codelineno-43-10" href="#__codelineno-43-10"></a><span class="w"> </span><span class="nx">dp</span><span class="p">[</span><span class="mi">2</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">2</span>
|
||||
<a id="__codelineno-43-11" name="__codelineno-43-11" href="#__codelineno-43-11"></a><span class="w"> </span><span class="c1">// Переход состояний: постепенное решение больших подзадач через меньшие</span>
|
||||
<a id="__codelineno-43-12" name="__codelineno-43-12" href="#__codelineno-43-12"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="mi">3</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o"><=</span><span class="w"> </span><span class="nx">n</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="w"> </span><span class="p">{</span>
|
||||
<a id="__codelineno-43-13" name="__codelineno-43-13" href="#__codelineno-43-13"></a><span class="w"> </span><span class="nx">dp</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nx">dp</span><span class="p">[</span><span class="nx">i</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">dp</span><span class="p">[</span><span class="nx">i</span><span class="o">-</span><span class="mi">2</span><span class="p">]</span>
|
||||
<a id="__codelineno-43-13" name="__codelineno-43-13" href="#__codelineno-43-13"></a><span class="w"> </span><span class="nx">dp</span><span class="p">[</span><span class="nx">i</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">dp</span><span class="p">[</span><span class="nx">i</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="nx">dp</span><span class="p">[</span><span class="nx">i</span><span class="o">-</span><span class="mi">2</span><span class="p">]</span>
|
||||
<a id="__codelineno-43-14" name="__codelineno-43-14" href="#__codelineno-43-14"></a><span class="w"> </span><span class="p">}</span>
|
||||
<a id="__codelineno-43-15" name="__codelineno-43-15" href="#__codelineno-43-15"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">dp</span><span class="p">[</span><span class="nx">n</span><span class="p">]</span>
|
||||
<a id="__codelineno-43-16" name="__codelineno-43-16" href="#__codelineno-43-16"></a><span class="p">}</span>
|
||||
@@ -5916,7 +5924,7 @@ dp[i] = dp[i-1] + dp[i-2]
|
||||
</div>
|
||||
<details class="pythontutor">
|
||||
<summary>Визуализация кода</summary>
|
||||
<p><div style="height: 549px; width: 100%;"><iframe class="pythontutor-iframe" src="https://pythontutor.com/iframe-embed.html#code=def%20climbing_stairs_dp%28n%3A%20int%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%9F%D0%BE%D0%B4%D1%8A%D0%B5%D0%BC%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%3A%20%D0%B4%D0%B8%D0%BD%D0%B0%D0%BC%D0%B8%D1%87%D0%B5%D1%81%D0%BA%D0%BE%D0%B5%20%D0%BF%D1%80%D0%BE%D0%B3%D1%80%D0%B0%D0%BC%D0%BC%D0%B8%D1%80%D0%BE%D0%B2%D0%B0%D0%BD%D0%B8%D0%B5%22%22%22%0A%20%20%20%20if%20n%20%3D%3D%201%20or%20n%20%3D%3D%202%3A%0A%20%20%20%20%20%20%20%20return%20n%0A%20%20%20%20%23%20%D0%98%D0%BD%D0%B8%D1%86%D0%B8%D0%B0%D0%BB%D0%B8%D0%B7%D0%B0%D1%86%D0%B8%D1%8F%20%D1%82%D0%B0%D0%B1%D0%BB%D0%B8%D1%86%D1%8B%20dp%20%D0%B4%D0%BB%D1%8F%20%D1%85%D1%80%D0%B0%D0%BD%D0%B5%D0%BD%D0%B8%D1%8F%20%D1%80%D0%B5%D1%88%D0%B5%D0%BD%D0%B8%D0%B9%20%D0%BF%D0%BE%D0%B4%D0%B7%D0%B0%D0%B4%D0%B0%D1%87%0A%20%20%20%20dp%20%3D%20%5B0%5D%20%2A%20%28n%20%2B%201%29%0A%20%20%20%20%23%20%D0%9D%D0%B0%D1%87%D0%B0%D0%BB%D1%8C%D0%BD%D0%BE%D0%B5%20%D1%81%D0%BE%D1%81%D1%82%D0%BE%D1%8F%D0%BD%D0%B8%D0%B5%3A%20%D0%B7%D0%B0%D1%80%D0%B0%D0%BD%D0%B5%D0%B5%20%D0%B7%D0%B0%D0%B4%D0%B0%D1%82%D1%8C%20%D1%80%D0%B5%D1%88%D0%B5%D0%BD%D0%B8%D1%8F%20%D0%BD%D0%B0%D0%B8%D0%BC%D0%B5%D0%BD%D1%8C%D1%88%D0%B8%D1%85%20%D0%BF%D0%BE%D0%B4%D0%B7%D0%B0%D0%B4%D0%B0%D1%87%0A%20%20%20%20dp%5B1%5D%2C%20dp%5B2%5D%20%3D%201%2C%202%0A%20%20%20%20%23%20%D0%9F%D0%B5%D1%80%D0%B5%D1%85%D0%BE%D0%B4%20%D1%81%D0%BE%D1%81%D1%82%D0%BE%D1%8F%D0%BD%D0%B8%D0%B9%3A%20%D0%BF%D0%BE%D1%81%D1%82%D0%B5%D0%BF%D0%B5%D0%BD%D0%BD%D0%BE%D0%B5%20%D1%80%D0%B5%D1%88%D0%B5%D0%BD%D0%B8%D0%B5%20%D0%B1%D0%BE%D0%BB%D1%8C%D1%88%D0%B8%D1%85%20%D0%BF%D0%BE%D0%B4%D0%B7%D0%B0%D0%B4%D0%B0%D1%87%20%D1%87%D0%B5%D1%80%D0%B5%D0%B7%20%D0%BC%D0%B5%D0%BD%D1%8C%D1%88%D0%B8%D0%B5%0A%20%20%20%20for%20i%20in%20range%283%2C%20n%20%2B%201%29%3A%0A%20%20%20%20%20%20%20%20dp%5Bi%5D%20%3D%20dp%5Bi%20-%201%5D%20%2B%20dp%5Bi%20-%202%5D%0A%20%20%20%20return%20dp%5Bn%5D%0A%0A%0A%22%22%22Driver%20Code%22%22%22%0Aif%20__name__%20%3D%3D%20%22__main__%22%3A%0A%20%20%20%20n%20%3D%209%0A%0A%20%20%20%20res%20%3D%20climbing_stairs_dp%28n%29%0A%20%20%20%20print%28f%22%D0%9A%D0%BE%D0%BB%D0%B8%D1%87%D0%B5%D1%81%D1%82%D0%B2%D0%BE%20%D1%81%D0%BF%D0%BE%D1%81%D0%BE%D0%B1%D0%BE%D0%B2%20%D0%BF%D0%BE%D0%B4%D0%BD%D1%8F%D1%82%D1%8C%D1%81%D1%8F%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%20%D0%B8%D0%B7%20%7Bn%7D%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B5%D0%B9%20%3D%20%7Bres%7D%22%29&codeDivHeight=472&codeDivWidth=350&cumulative=false&curInstr=4&heapPrimitives=nevernest&origin=opt-frontend.js&py=311&rawInputLstJSON=%5B%5D&textReferences=false"> </iframe></div>
|
||||
<p><div style="height: 549px; width: 100%;"><iframe class="pythontutor-iframe" title="Визуализация кода" src="https://pythontutor.com/iframe-embed.html#code=def%20climbing_stairs_dp%28n%3A%20int%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%9F%D0%BE%D0%B4%D1%8A%D0%B5%D0%BC%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%3A%20%D0%B4%D0%B8%D0%BD%D0%B0%D0%BC%D0%B8%D1%87%D0%B5%D1%81%D0%BA%D0%BE%D0%B5%20%D0%BF%D1%80%D0%BE%D0%B3%D1%80%D0%B0%D0%BC%D0%BC%D0%B8%D1%80%D0%BE%D0%B2%D0%B0%D0%BD%D0%B8%D0%B5%22%22%22%0A%20%20%20%20if%20n%20%3D%3D%201%20or%20n%20%3D%3D%202%3A%0A%20%20%20%20%20%20%20%20return%20n%0A%20%20%20%20%23%20%D0%98%D0%BD%D0%B8%D1%86%D0%B8%D0%B0%D0%BB%D0%B8%D0%B7%D0%B0%D1%86%D0%B8%D1%8F%20%D1%82%D0%B0%D0%B1%D0%BB%D0%B8%D1%86%D1%8B%20dp%20%D0%B4%D0%BB%D1%8F%20%D1%85%D1%80%D0%B0%D0%BD%D0%B5%D0%BD%D0%B8%D1%8F%20%D1%80%D0%B5%D1%88%D0%B5%D0%BD%D0%B8%D0%B9%20%D0%BF%D0%BE%D0%B4%D0%B7%D0%B0%D0%B4%D0%B0%D1%87%0A%20%20%20%20dp%20%3D%20%5B0%5D%20%2A%20%28n%20%2B%201%29%0A%20%20%20%20%23%20%D0%9D%D0%B0%D1%87%D0%B0%D0%BB%D1%8C%D0%BD%D0%BE%D0%B5%20%D1%81%D0%BE%D1%81%D1%82%D0%BE%D1%8F%D0%BD%D0%B8%D0%B5%3A%20%D0%B7%D0%B0%D1%80%D0%B0%D0%BD%D0%B5%D0%B5%20%D0%B7%D0%B0%D0%B4%D0%B0%D1%82%D1%8C%20%D1%80%D0%B5%D1%88%D0%B5%D0%BD%D0%B8%D1%8F%20%D0%BD%D0%B0%D0%B8%D0%BC%D0%B5%D0%BD%D1%8C%D1%88%D0%B8%D1%85%20%D0%BF%D0%BE%D0%B4%D0%B7%D0%B0%D0%B4%D0%B0%D1%87%0A%20%20%20%20dp%5B1%5D%2C%20dp%5B2%5D%20%3D%201%2C%202%0A%20%20%20%20%23%20%D0%9F%D0%B5%D1%80%D0%B5%D1%85%D0%BE%D0%B4%20%D1%81%D0%BE%D1%81%D1%82%D0%BE%D1%8F%D0%BD%D0%B8%D0%B9%3A%20%D0%BF%D0%BE%D1%81%D1%82%D0%B5%D0%BF%D0%B5%D0%BD%D0%BD%D0%BE%D0%B5%20%D1%80%D0%B5%D1%88%D0%B5%D0%BD%D0%B8%D0%B5%20%D0%B1%D0%BE%D0%BB%D1%8C%D1%88%D0%B8%D1%85%20%D0%BF%D0%BE%D0%B4%D0%B7%D0%B0%D0%B4%D0%B0%D1%87%20%D1%87%D0%B5%D1%80%D0%B5%D0%B7%20%D0%BC%D0%B5%D0%BD%D1%8C%D1%88%D0%B8%D0%B5%0A%20%20%20%20for%20i%20in%20range%283%2C%20n%20%2B%201%29%3A%0A%20%20%20%20%20%20%20%20dp%5Bi%5D%20%3D%20dp%5Bi%20-%201%5D%20%2B%20dp%5Bi%20-%202%5D%0A%20%20%20%20return%20dp%5Bn%5D%0A%0A%0A%22%22%22Driver%20Code%22%22%22%0Aif%20__name__%20%3D%3D%20%22__main__%22%3A%0A%20%20%20%20n%20%3D%209%0A%0A%20%20%20%20res%20%3D%20climbing_stairs_dp%28n%29%0A%20%20%20%20print%28f%22%D0%9A%D0%BE%D0%BB%D0%B8%D1%87%D0%B5%D1%81%D1%82%D0%B2%D0%BE%20%D1%81%D0%BF%D0%BE%D1%81%D0%BE%D0%B1%D0%BE%D0%B2%20%D0%BF%D0%BE%D0%B4%D0%BD%D1%8F%D1%82%D1%8C%D1%81%D1%8F%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%20%D0%B8%D0%B7%20%7Bn%7D%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B5%D0%B9%20%3D%20%7Bres%7D%22%29&codeDivHeight=472&codeDivWidth=350&cumulative=false&curInstr=4&heapPrimitives=nevernest&origin=opt-frontend.js&py=311&rawInputLstJSON=%5B%5D&textReferences=false"> </iframe></div>
|
||||
<div style="margin-top: 5px;"><a href="https://pythontutor.com/iframe-embed.html#code=def%20climbing_stairs_dp%28n%3A%20int%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%9F%D0%BE%D0%B4%D1%8A%D0%B5%D0%BC%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%3A%20%D0%B4%D0%B8%D0%BD%D0%B0%D0%BC%D0%B8%D1%87%D0%B5%D1%81%D0%BA%D0%BE%D0%B5%20%D0%BF%D1%80%D0%BE%D0%B3%D1%80%D0%B0%D0%BC%D0%BC%D0%B8%D1%80%D0%BE%D0%B2%D0%B0%D0%BD%D0%B8%D0%B5%22%22%22%0A%20%20%20%20if%20n%20%3D%3D%201%20or%20n%20%3D%3D%202%3A%0A%20%20%20%20%20%20%20%20return%20n%0A%20%20%20%20%23%20%D0%98%D0%BD%D0%B8%D1%86%D0%B8%D0%B0%D0%BB%D0%B8%D0%B7%D0%B0%D1%86%D0%B8%D1%8F%20%D1%82%D0%B0%D0%B1%D0%BB%D0%B8%D1%86%D1%8B%20dp%20%D0%B4%D0%BB%D1%8F%20%D1%85%D1%80%D0%B0%D0%BD%D0%B5%D0%BD%D0%B8%D1%8F%20%D1%80%D0%B5%D1%88%D0%B5%D0%BD%D0%B8%D0%B9%20%D0%BF%D0%BE%D0%B4%D0%B7%D0%B0%D0%B4%D0%B0%D1%87%0A%20%20%20%20dp%20%3D%20%5B0%5D%20%2A%20%28n%20%2B%201%29%0A%20%20%20%20%23%20%D0%9D%D0%B0%D1%87%D0%B0%D0%BB%D1%8C%D0%BD%D0%BE%D0%B5%20%D1%81%D0%BE%D1%81%D1%82%D0%BE%D1%8F%D0%BD%D0%B8%D0%B5%3A%20%D0%B7%D0%B0%D1%80%D0%B0%D0%BD%D0%B5%D0%B5%20%D0%B7%D0%B0%D0%B4%D0%B0%D1%82%D1%8C%20%D1%80%D0%B5%D1%88%D0%B5%D0%BD%D0%B8%D1%8F%20%D0%BD%D0%B0%D0%B8%D0%BC%D0%B5%D0%BD%D1%8C%D1%88%D0%B8%D1%85%20%D0%BF%D0%BE%D0%B4%D0%B7%D0%B0%D0%B4%D0%B0%D1%87%0A%20%20%20%20dp%5B1%5D%2C%20dp%5B2%5D%20%3D%201%2C%202%0A%20%20%20%20%23%20%D0%9F%D0%B5%D1%80%D0%B5%D1%85%D0%BE%D0%B4%20%D1%81%D0%BE%D1%81%D1%82%D0%BE%D1%8F%D0%BD%D0%B8%D0%B9%3A%20%D0%BF%D0%BE%D1%81%D1%82%D0%B5%D0%BF%D0%B5%D0%BD%D0%BD%D0%BE%D0%B5%20%D1%80%D0%B5%D1%88%D0%B5%D0%BD%D0%B8%D0%B5%20%D0%B1%D0%BE%D0%BB%D1%8C%D1%88%D0%B8%D1%85%20%D0%BF%D0%BE%D0%B4%D0%B7%D0%B0%D0%B4%D0%B0%D1%87%20%D1%87%D0%B5%D1%80%D0%B5%D0%B7%20%D0%BC%D0%B5%D0%BD%D1%8C%D1%88%D0%B8%D0%B5%0A%20%20%20%20for%20i%20in%20range%283%2C%20n%20%2B%201%29%3A%0A%20%20%20%20%20%20%20%20dp%5Bi%5D%20%3D%20dp%5Bi%20-%201%5D%20%2B%20dp%5Bi%20-%202%5D%0A%20%20%20%20return%20dp%5Bn%5D%0A%0A%0A%22%22%22Driver%20Code%22%22%22%0Aif%20__name__%20%3D%3D%20%22__main__%22%3A%0A%20%20%20%20n%20%3D%209%0A%0A%20%20%20%20res%20%3D%20climbing_stairs_dp%28n%29%0A%20%20%20%20print%28f%22%D0%9A%D0%BE%D0%BB%D0%B8%D1%87%D0%B5%D1%81%D1%82%D0%B2%D0%BE%20%D1%81%D0%BF%D0%BE%D1%81%D0%BE%D0%B1%D0%BE%D0%B2%20%D0%BF%D0%BE%D0%B4%D0%BD%D1%8F%D1%82%D1%8C%D1%81%D1%8F%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%20%D0%B8%D0%B7%20%7Bn%7D%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B5%D0%B9%20%3D%20%7Bres%7D%22%29&codeDivHeight=800&codeDivWidth=600&cumulative=false&curInstr=4&heapPrimitives=nevernest&origin=opt-frontend.js&py=311&rawInputLstJSON=%5B%5D&textReferences=false" target="_blank" rel="noopener noreferrer">Во весь экран ></a></div></p>
|
||||
</details>
|
||||
<p>На рисунке 14-5 смоделирован процесс выполнения этого кода.</p>
|
||||
@@ -5936,7 +5944,7 @@ dp[i] = dp[i-1] + dp[i-2]
|
||||
<div class="tabbed-content">
|
||||
<div class="tabbed-block">
|
||||
<div class="highlight"><span class="filename">climbing_stairs_dp.py</span><pre><span></span><code><a id="__codelineno-52-1" name="__codelineno-52-1" href="#__codelineno-52-1"></a><span class="k">def</span><span class="w"> </span><span class="nf">climbing_stairs_dp_comp</span><span class="p">(</span><span class="n">n</span><span class="p">:</span> <span class="nb">int</span><span class="p">)</span> <span class="o">-></span> <span class="nb">int</span><span class="p">:</span>
|
||||
<a id="__codelineno-52-2" name="__codelineno-52-2" href="#__codelineno-52-2"></a><span class="w"> </span><span class="sd">"""Подъем по лестнице: динамическое программирование с оптимизацией памяти"""</span>
|
||||
<a id="__codelineno-52-2" name="__codelineno-52-2" href="#__codelineno-52-2"></a><span class="w"> </span><span class="sd">"""Подъем по лестнице: динамическое программирование с оптимизацией памяти"""</span>
|
||||
<a id="__codelineno-52-3" name="__codelineno-52-3" href="#__codelineno-52-3"></a> <span class="k">if</span> <span class="n">n</span> <span class="o">==</span> <span class="mi">1</span> <span class="ow">or</span> <span class="n">n</span> <span class="o">==</span> <span class="mi">2</span><span class="p">:</span>
|
||||
<a id="__codelineno-52-4" name="__codelineno-52-4" href="#__codelineno-52-4"></a> <span class="k">return</span> <span class="n">n</span>
|
||||
<a id="__codelineno-52-5" name="__codelineno-52-5" href="#__codelineno-52-5"></a> <span class="n">a</span><span class="p">,</span> <span class="n">b</span> <span class="o">=</span> <span class="mi">1</span><span class="p">,</span> <span class="mi">2</span>
|
||||
@@ -5999,7 +6007,7 @@ dp[i] = dp[i-1] + dp[i-2]
|
||||
<a id="__codelineno-56-6" name="__codelineno-56-6" href="#__codelineno-56-6"></a><span class="w"> </span><span class="nx">a</span><span class="p">,</span><span class="w"> </span><span class="nx">b</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="mi">1</span><span class="p">,</span><span class="w"> </span><span class="mi">2</span>
|
||||
<a id="__codelineno-56-7" name="__codelineno-56-7" href="#__codelineno-56-7"></a><span class="w"> </span><span class="c1">// Переход состояний: постепенное решение больших подзадач через меньшие</span>
|
||||
<a id="__codelineno-56-8" name="__codelineno-56-8" href="#__codelineno-56-8"></a><span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o">:=</span><span class="w"> </span><span class="mi">3</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="w"> </span><span class="o"><=</span><span class="w"> </span><span class="nx">n</span><span class="p">;</span><span class="w"> </span><span class="nx">i</span><span class="o">++</span><span class="w"> </span><span class="p">{</span>
|
||||
<a id="__codelineno-56-9" name="__codelineno-56-9" href="#__codelineno-56-9"></a><span class="w"> </span><span class="nx">a</span><span class="p">,</span><span class="w"> </span><span class="nx">b</span><span class="w"> </span><span class="p">=</span><span class="w"> </span><span class="nx">b</span><span class="p">,</span><span class="w"> </span><span class="nx">a</span><span class="o">+</span><span class="nx">b</span>
|
||||
<a id="__codelineno-56-9" name="__codelineno-56-9" href="#__codelineno-56-9"></a><span class="w"> </span><span class="nx">a</span><span class="p">,</span><span class="w"> </span><span class="nx">b</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nx">b</span><span class="p">,</span><span class="w"> </span><span class="nx">a</span><span class="o">+</span><span class="nx">b</span>
|
||||
<a id="__codelineno-56-10" name="__codelineno-56-10" href="#__codelineno-56-10"></a><span class="w"> </span><span class="p">}</span>
|
||||
<a id="__codelineno-56-11" name="__codelineno-56-11" href="#__codelineno-56-11"></a><span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="nx">b</span>
|
||||
<a id="__codelineno-56-12" name="__codelineno-56-12" href="#__codelineno-56-12"></a><span class="p">}</span>
|
||||
@@ -6126,7 +6134,7 @@ dp[i] = dp[i-1] + dp[i-2]
|
||||
</div>
|
||||
<details class="pythontutor">
|
||||
<summary>Визуализация кода</summary>
|
||||
<p><div style="height: 477px; width: 100%;"><iframe class="pythontutor-iframe" src="https://pythontutor.com/iframe-embed.html#code=def%20climbing_stairs_dp_comp%28n%3A%20int%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%9F%D0%BE%D0%B4%D1%8A%D0%B5%D0%BC%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%3A%20%D0%B4%D0%B8%D0%BD%D0%B0%D0%BC%D0%B8%D1%87%D0%B5%D1%81%D0%BA%D0%BE%D0%B5%20%D0%BF%D1%80%D0%BE%D0%B3%D1%80%D0%B0%D0%BC%D0%BC%D0%B8%D1%80%D0%BE%D0%B2%D0%B0%D0%BD%D0%B8%D0%B5%20%D1%81%20%D0%BE%D0%BF%D1%82%D0%B8%D0%BC%D0%B8%D0%B7%D0%B0%D1%86%D0%B8%D0%B5%D0%B9%20%D0%BF%D0%B0%D0%BC%D1%8F%D1%82%D0%B8%22%22%22%0A%20%20%20%20if%20n%20%3D%3D%201%20or%20n%20%3D%3D%202%3A%0A%20%20%20%20%20%20%20%20return%20n%0A%20%20%20%20a%2C%20b%20%3D%201%2C%202%0A%20%20%20%20for%20_%20in%20range%283%2C%20n%20%2B%201%29%3A%0A%20%20%20%20%20%20%20%20a%2C%20b%20%3D%20b%2C%20a%20%2B%20b%0A%20%20%20%20return%20b%0A%0A%0A%22%22%22Driver%20Code%22%22%22%0Aif%20__name__%20%3D%3D%20%22__main__%22%3A%0A%20%20%20%20n%20%3D%209%0A%0A%20%20%20%20res%20%3D%20climbing_stairs_dp_comp%28n%29%0A%20%20%20%20print%28f%22%D0%9A%D0%BE%D0%BB%D0%B8%D1%87%D0%B5%D1%81%D1%82%D0%B2%D0%BE%20%D1%81%D0%BF%D0%BE%D1%81%D0%BE%D0%B1%D0%BE%D0%B2%20%D0%BF%D0%BE%D0%B4%D0%BD%D1%8F%D1%82%D1%8C%D1%81%D1%8F%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%20%D0%B8%D0%B7%20%7Bn%7D%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B5%D0%B9%20%3D%20%7Bres%7D%22%29&codeDivHeight=472&codeDivWidth=350&cumulative=false&curInstr=4&heapPrimitives=nevernest&origin=opt-frontend.js&py=311&rawInputLstJSON=%5B%5D&textReferences=false"> </iframe></div>
|
||||
<p><div style="height: 477px; width: 100%;"><iframe class="pythontutor-iframe" title="Визуализация кода" src="https://pythontutor.com/iframe-embed.html#code=def%20climbing_stairs_dp_comp%28n%3A%20int%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%9F%D0%BE%D0%B4%D1%8A%D0%B5%D0%BC%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%3A%20%D0%B4%D0%B8%D0%BD%D0%B0%D0%BC%D0%B8%D1%87%D0%B5%D1%81%D0%BA%D0%BE%D0%B5%20%D0%BF%D1%80%D0%BE%D0%B3%D1%80%D0%B0%D0%BC%D0%BC%D0%B8%D1%80%D0%BE%D0%B2%D0%B0%D0%BD%D0%B8%D0%B5%20%D1%81%20%D0%BE%D0%BF%D1%82%D0%B8%D0%BC%D0%B8%D0%B7%D0%B0%D1%86%D0%B8%D0%B5%D0%B9%20%D0%BF%D0%B0%D0%BC%D1%8F%D1%82%D0%B8%22%22%22%0A%20%20%20%20if%20n%20%3D%3D%201%20or%20n%20%3D%3D%202%3A%0A%20%20%20%20%20%20%20%20return%20n%0A%20%20%20%20a%2C%20b%20%3D%201%2C%202%0A%20%20%20%20for%20_%20in%20range%283%2C%20n%20%2B%201%29%3A%0A%20%20%20%20%20%20%20%20a%2C%20b%20%3D%20b%2C%20a%20%2B%20b%0A%20%20%20%20return%20b%0A%0A%0A%22%22%22Driver%20Code%22%22%22%0Aif%20__name__%20%3D%3D%20%22__main__%22%3A%0A%20%20%20%20n%20%3D%209%0A%0A%20%20%20%20res%20%3D%20climbing_stairs_dp_comp%28n%29%0A%20%20%20%20print%28f%22%D0%9A%D0%BE%D0%BB%D0%B8%D1%87%D0%B5%D1%81%D1%82%D0%B2%D0%BE%20%D1%81%D0%BF%D0%BE%D1%81%D0%BE%D0%B1%D0%BE%D0%B2%20%D0%BF%D0%BE%D0%B4%D0%BD%D1%8F%D1%82%D1%8C%D1%81%D1%8F%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%20%D0%B8%D0%B7%20%7Bn%7D%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B5%D0%B9%20%3D%20%7Bres%7D%22%29&codeDivHeight=472&codeDivWidth=350&cumulative=false&curInstr=4&heapPrimitives=nevernest&origin=opt-frontend.js&py=311&rawInputLstJSON=%5B%5D&textReferences=false"> </iframe></div>
|
||||
<div style="margin-top: 5px;"><a href="https://pythontutor.com/iframe-embed.html#code=def%20climbing_stairs_dp_comp%28n%3A%20int%29%20-%3E%20int%3A%0A%20%20%20%20%22%22%22%D0%9F%D0%BE%D0%B4%D1%8A%D0%B5%D0%BC%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%3A%20%D0%B4%D0%B8%D0%BD%D0%B0%D0%BC%D0%B8%D1%87%D0%B5%D1%81%D0%BA%D0%BE%D0%B5%20%D0%BF%D1%80%D0%BE%D0%B3%D1%80%D0%B0%D0%BC%D0%BC%D0%B8%D1%80%D0%BE%D0%B2%D0%B0%D0%BD%D0%B8%D0%B5%20%D1%81%20%D0%BE%D0%BF%D1%82%D0%B8%D0%BC%D0%B8%D0%B7%D0%B0%D1%86%D0%B8%D0%B5%D0%B9%20%D0%BF%D0%B0%D0%BC%D1%8F%D1%82%D0%B8%22%22%22%0A%20%20%20%20if%20n%20%3D%3D%201%20or%20n%20%3D%3D%202%3A%0A%20%20%20%20%20%20%20%20return%20n%0A%20%20%20%20a%2C%20b%20%3D%201%2C%202%0A%20%20%20%20for%20_%20in%20range%283%2C%20n%20%2B%201%29%3A%0A%20%20%20%20%20%20%20%20a%2C%20b%20%3D%20b%2C%20a%20%2B%20b%0A%20%20%20%20return%20b%0A%0A%0A%22%22%22Driver%20Code%22%22%22%0Aif%20__name__%20%3D%3D%20%22__main__%22%3A%0A%20%20%20%20n%20%3D%209%0A%0A%20%20%20%20res%20%3D%20climbing_stairs_dp_comp%28n%29%0A%20%20%20%20print%28f%22%D0%9A%D0%BE%D0%BB%D0%B8%D1%87%D0%B5%D1%81%D1%82%D0%B2%D0%BE%20%D1%81%D0%BF%D0%BE%D1%81%D0%BE%D0%B1%D0%BE%D0%B2%20%D0%BF%D0%BE%D0%B4%D0%BD%D1%8F%D1%82%D1%8C%D1%81%D1%8F%20%D0%BF%D0%BE%20%D0%BB%D0%B5%D1%81%D1%82%D0%BD%D0%B8%D1%86%D0%B5%20%D0%B8%D0%B7%20%7Bn%7D%20%D1%81%D1%82%D1%83%D0%BF%D0%B5%D0%BD%D0%B5%D0%B9%20%3D%20%7Bres%7D%22%29&codeDivHeight=800&codeDivWidth=600&cumulative=false&curInstr=4&heapPrimitives=nevernest&origin=opt-frontend.js&py=311&rawInputLstJSON=%5B%5D&textReferences=false" target="_blank" rel="noopener noreferrer">Во весь экран ></a></div></p>
|
||||
</details>
|
||||
<p>Из кода видно, что после отказа от массива <code>dp</code> пространственная сложность уменьшается с <span class="arithmatex">\(O(n)\)</span> до <span class="arithmatex">\(O(1)\)</span> .</p>
|
||||
@@ -6239,6 +6247,8 @@ aria-label="Нижний колонтитул"
|
||||
/* Set palette on initial load */
|
||||
giscus.setAttribute("data-theme", getGiscusTheme())
|
||||
|
||||
|
||||
|
||||
/* Register event handlers after documented loaded */
|
||||
document.addEventListener("DOMContentLoaded", function() {
|
||||
var ref = document.querySelector("[data-md-component=palette]")
|
||||
@@ -6336,7 +6346,7 @@ aria-label="Нижний колонтитул"
|
||||
<script id="__config" type="application/json">{"annotate":null,"base":"../../","features":["content.action.edit","content.code.annotate","content.code.copy","content.tabs.link","content.tooltips","navigation.indexes","navigation.tracking","search.highlight","search.share","search.suggest","toc.follow"],"search":"../../assets/javascripts/workers/search.b6b7e04f.min.js","tags":null,"translations":{"clipboard.copied":"Скопировано в буфер","clipboard.copy":"Копировать в буфер","search.result.more.one":"Ещё 1 на этой странице","search.result.more.other":"Ещё # на этой странице","search.result.none":"Совпадений не найдено","search.result.one":"Найдено 1 совпадение","search.result.other":"Найдено совпадений: #","search.result.placeholder":"Начните печатать для поиска","search.result.term.missing":"Отсутствует","select.version":"Выберите версию"},"version":null}</script>
|
||||
|
||||
|
||||
<script src="../../assets/javascripts/bundle.d7f30b55.min.js"></script>
|
||||
<script src="../../assets/javascripts/bundle.e559d5b757c25f1f23bd887b700c56e3018b129d471c011292faeb47b8b74ce4.min.js"></script>
|
||||
|
||||
<script src="../../javascripts/mathjax.js"></script>
|
||||
|
||||
|
||||
Reference in New Issue
Block a user