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<div id="projectbrief">All the algorithms implemented in C++</div>
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<p>Implementation for [LFU Cache] (<a href="https://en.wikipedia.org/wiki/Least_frequently_used">https://en.wikipedia.org/wiki/Least_frequently_used</a>)
<a href="#details">More...</a></p>
<div class="textblock"><code>#include &lt;cassert&gt;</code><br />
<code>#include &lt;iostream&gt;</code><br />
<code>#include &lt;unordered_map&gt;</code><br />
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Include dependency graph for lfu_cache.cpp:</div>
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<p><a href="../../d9/d65/lfu__cache_8cpp_source.html">Go to the source code of this file.</a></p>
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Classes</h2></td></tr>
<tr class="memitem:others_3A_3ACache_3A_3AD_5FNode_3C_20T_20_3E" id="r_others_3A_3ACache_3A_3AD_5FNode_3C_20T_20_3E"><td class="memItemLeft" align="right" valign="top">class &#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="../../de/d21/classothers_1_1_cache_1_1_d___node.html">others::Cache::D_Node&lt; T &gt;</a></td></tr>
<tr class="memdesc:"><td class="mdescLeft">&#160;</td><td class="mdescRight"><a class="el" href="../../db/d8b/struct_node.html">Node</a> for a doubly linked list with data, prev and next pointers. <a href="../../de/d21/classothers_1_1_cache_1_1_d___node.html#details">More...</a><br /></td></tr>
<tr class="memitem:others_3A_3ACache_3A_3ALFUCache_3C_20K_2C_20V_20_3E" id="r_others_3A_3ACache_3A_3ALFUCache_3C_20K_2C_20V_20_3E"><td class="memItemLeft" align="right" valign="top">class &#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="../../df/d8f/classothers_1_1_cache_1_1_l_f_u_cache.html">others::Cache::LFUCache&lt; K, V &gt;</a></td></tr>
<tr class="memdesc:"><td class="mdescLeft">&#160;</td><td class="mdescRight"><a class="el" href="../../df/d8f/classothers_1_1_cache_1_1_l_f_u_cache.html" title="LFUCache.">LFUCache</a>. <a href="../../df/d8f/classothers_1_1_cache_1_1_l_f_u_cache.html#details">More...</a><br /></td></tr>
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Namespaces</h2></td></tr>
<tr class="memitem:others" id="r_others"><td class="memItemLeft" align="right" valign="top">namespace &#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="../../d0/d6f/namespaceothers.html">others</a></td></tr>
<tr class="memdesc:d0/d6f/namespaceothers"><td class="mdescLeft">&#160;</td><td class="mdescRight">for <span class="tt">vector</span> <br /></td></tr>
<tr class="memitem:others_3A_3ACache" id="r_others_3A_3ACache"><td class="memItemLeft" align="right" valign="top">namespace &#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="../../db/dde/namespaceothers_1_1_cache.html">others::Cache</a></td></tr>
<tr class="memdesc:db/dde/namespaceothers_1_1_cache"><td class="mdescLeft">&#160;</td><td class="mdescRight"><a class="el" href="../../db/dde/namespaceothers_1_1_cache.html" title="Cache algorithm.">Cache</a> algorithm. <br /></td></tr>
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<tr class="memitem:a5c0dfbf62803f020205076c3da18d058" id="r_a5c0dfbf62803f020205076c3da18d058"><td class="memTemplParams" colspan="2">template&lt;typename K, typename V&gt; </td></tr>
<tr class="memitem:a5c0dfbf62803f020205076c3da18d058 template"><td class="memItemLeft" align="right" valign="top">using&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="../../db/dde/namespaceothers_1_1_cache.html#a5c0dfbf62803f020205076c3da18d058">others::Cache::CacheNode</a> = <a class="el" href="../../de/d21/classothers_1_1_cache_1_1_d___node.html">D_Node</a>&lt;std::pair&lt;K, V&gt;&gt;</td></tr>
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Functions</h2></td></tr>
<tr class="memitem:aa8dca7b867074164d5f45b0f3851269d" id="r_aa8dca7b867074164d5f45b0f3851269d"><td class="memItemLeft" align="right" valign="top">static void&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="#aa8dca7b867074164d5f45b0f3851269d">test</a> ()</td></tr>
<tr class="memdesc:aa8dca7b867074164d5f45b0f3851269d"><td class="mdescLeft">&#160;</td><td class="mdescRight">self test implementation <br /></td></tr>
<tr class="memitem:ae66f6b31b5ad750f1fe042a706a4e3d4" id="r_ae66f6b31b5ad750f1fe042a706a4e3d4"><td class="memItemLeft" align="right" valign="top">int&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="#ae66f6b31b5ad750f1fe042a706a4e3d4">main</a> ()</td></tr>
<tr class="memdesc:ae66f6b31b5ad750f1fe042a706a4e3d4"><td class="mdescLeft">&#160;</td><td class="mdescRight">main function <br /></td></tr>
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<a name="details" id="details"></a><h2 id="header-details" class="groupheader">Detailed Description</h2>
<div class="textblock"><p>Implementation for [LFU Cache] (<a href="https://en.wikipedia.org/wiki/Least_frequently_used">https://en.wikipedia.org/wiki/Least_frequently_used</a>) </p>
<p>LFU discards the least frequently used value. if there are multiple items with the same minimum frequency then, the least recently used among them is discarded. Data structures used - doubly linked list and unordered_map(hash
map).</p>
<p>Hashmap maps the key to the address of the node of the linked list and its current usage frequency. If the element is accessed the element is removed from the linked list of the current frequency and added to the linked list of incremented frequency.</p>
<p>When the cache is full, the last element in the minimum frequency linked list is popped.</p>
<dl class="section author"><dt>Author</dt><dd><a href="https://github.com/deDSeC00720" target="_blank">Karan Sharma</a> </dd></dl>
<p class="definition">Definition in file <a class="el" href="../../d9/d65/lfu__cache_8cpp_source.html">lfu_cache.cpp</a>.</p>
</div><a name="doc-func-members" id="doc-func-members"></a><h2 id="header-doc-func-members" class="groupheader">Function Documentation</h2>
<a id="ae66f6b31b5ad750f1fe042a706a4e3d4" name="ae66f6b31b5ad750f1fe042a706a4e3d4"></a>
<h2 class="memtitle"><span class="permalink"><a href="#ae66f6b31b5ad750f1fe042a706a4e3d4">&#9670;&#160;</a></span>main()</h2>
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<td class="memname">int main </td>
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<p>main function </p>
<dl class="section return"><dt>Returns</dt><dd>0 on exit </dd></dl>
<p class="definition">Definition at line <a class="el" href="../../d9/d65/lfu__cache_8cpp_source.html#l00301">301</a> of file <a class="el" href="../../d9/d65/lfu__cache_8cpp_source.html">lfu_cache.cpp</a>.</p>
<div class="fragment"><div class="line"><span class="lineno"> 301</span> {</div>
<div class="line"><span class="lineno"> 302</span> <a class="code hl_function" href="#aa8dca7b867074164d5f45b0f3851269d">test</a>(); <span class="comment">// run the self test implementation</span></div>
<div class="line"><span class="lineno"> 303</span> <span class="keywordflow">return</span> 0;</div>
<div class="line"><span class="lineno"> 304</span>}</div>
<div class="ttc" id="alfu__cache_8cpp_html_aa8dca7b867074164d5f45b0f3851269d"><div class="ttname"><a href="#aa8dca7b867074164d5f45b0f3851269d">test</a></div><div class="ttdeci">static void test()</div><div class="ttdoc">self test implementation</div><div class="ttdef"><b>Definition</b> <a href="../../d9/d65/lfu__cache_8cpp_source.html#l00250">lfu_cache.cpp:250</a></div></div>
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<h2 class="memtitle"><span class="permalink"><a href="#aa8dca7b867074164d5f45b0f3851269d">&#9670;&#160;</a></span>test()</h2>
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<td class="memname">void test </td>
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<td class="paramname"><span class="paramname"><em></em></span></td><td>)</td>
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<p>self test implementation </p>
<dl class="section return"><dt>Returns</dt><dd>void </dd></dl>
<p class="definition">Definition at line <a class="el" href="../../d9/d65/lfu__cache_8cpp_source.html#l00250">250</a> of file <a class="el" href="../../d9/d65/lfu__cache_8cpp_source.html">lfu_cache.cpp</a>.</p>
<div class="fragment"><div class="line"><span class="lineno"> 250</span> {</div>
<div class="line"><span class="lineno"> 251</span> <a class="code hl_class" href="../../df/d8f/classothers_1_1_cache_1_1_l_f_u_cache.html">others::Cache::LFUCache&lt;int, int&gt;</a> cache(5);</div>
<div class="line"><span class="lineno"> 252</span> </div>
<div class="line"><span class="lineno"> 253</span> <span class="comment">// test the initial state of the cache</span></div>
<div class="line"><span class="lineno"> 254</span> assert(cache.size() == 0);</div>
<div class="line"><span class="lineno"> 255</span> assert(cache.capacity() == 5);</div>
<div class="line"><span class="lineno"> 256</span> assert(cache.empty());</div>
<div class="line"><span class="lineno"> 257</span> </div>
<div class="line"><span class="lineno"> 258</span> <span class="comment">// test insertion in the cache</span></div>
<div class="line"><span class="lineno"> 259</span> cache.put(1, 10);</div>
<div class="line"><span class="lineno"> 260</span> cache.put(-2, 20);</div>
<div class="line"><span class="lineno"> 261</span> </div>
<div class="line"><span class="lineno"> 262</span> <span class="comment">// test the state of cache after inserting some items</span></div>
<div class="line"><span class="lineno"> 263</span> assert(cache.size() == 2);</div>
<div class="line"><span class="lineno"> 264</span> assert(cache.capacity() == 5);</div>
<div class="line"><span class="lineno"> 265</span> assert(!cache.empty());</div>
<div class="line"><span class="lineno"> 266</span> </div>
<div class="line"><span class="lineno"> 267</span> <span class="comment">// test getting items from the cache</span></div>
<div class="line"><span class="lineno"> 268</span> assert(cache.get(1) == 10);</div>
<div class="line"><span class="lineno"> 269</span> assert(cache.get(-2) == 20);</div>
<div class="line"><span class="lineno"> 270</span> </div>
<div class="line"><span class="lineno"> 271</span> cache.put(-3, -30);</div>
<div class="line"><span class="lineno"> 272</span> cache.put(4, 40);</div>
<div class="line"><span class="lineno"> 273</span> cache.put(5, -50);</div>
<div class="line"><span class="lineno"> 274</span> cache.put(6, 60);</div>
<div class="line"><span class="lineno"> 275</span> </div>
<div class="line"><span class="lineno"> 276</span> <span class="comment">// test the state after inserting more items than the capacity</span></div>
<div class="line"><span class="lineno"> 277</span> assert(cache.size() == 5);</div>
<div class="line"><span class="lineno"> 278</span> assert(cache.capacity() == 5);</div>
<div class="line"><span class="lineno"> 279</span> assert(!cache.empty());</div>
<div class="line"><span class="lineno"> 280</span> </div>
<div class="line"><span class="lineno"> 281</span> <span class="comment">// test retrieval of all items in the cache</span></div>
<div class="line"><span class="lineno"> 282</span> assert(cache.get(1) == 10);</div>
<div class="line"><span class="lineno"> 283</span> assert(cache.get(-2) == 20);</div>
<div class="line"><span class="lineno"> 284</span> </div>
<div class="line"><span class="lineno"> 285</span> <span class="comment">// fetching -3 throws runtime_error</span></div>
<div class="line"><span class="lineno"> 286</span> <span class="comment">// as -3 was evicted being the least frequently used</span></div>
<div class="line"><span class="lineno"> 287</span> <span class="comment">// when 6 was added</span></div>
<div class="line"><span class="lineno"> 288</span> <span class="comment">// assert(cache.get(-3) == -30);</span></div>
<div class="line"><span class="lineno"> 289</span> </div>
<div class="line"><span class="lineno"> 290</span> assert(cache.get(4) == 40);</div>
<div class="line"><span class="lineno"> 291</span> assert(cache.get(5) == -50);</div>
<div class="line"><span class="lineno"> 292</span> assert(cache.get(6) == 60);</div>
<div class="line"><span class="lineno"> 293</span> </div>
<div class="line"><span class="lineno"> 294</span> std::cout &lt;&lt; <span class="stringliteral">&quot;test - passed\n&quot;</span>;</div>
<div class="line"><span class="lineno"> 295</span>}</div>
<div class="ttc" id="aclassothers_1_1_cache_1_1_l_f_u_cache_html"><div class="ttname"><a href="../../df/d8f/classothers_1_1_cache_1_1_l_f_u_cache.html">others::Cache::LFUCache</a></div><div class="ttdoc">LFUCache.</div><div class="ttdef"><b>Definition</b> <a href="../../d9/d65/lfu__cache_8cpp_source.html#l00064">lfu_cache.cpp:64</a></div></div>
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