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<a href="#func-members">Functions</a> </div>
<div class="headertitle"><div class="title">bit_manipulation Namespace Reference</div></div>
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<p>for IO operations
<a href="#details">More...</a></p>
<table class="memberdecls">
<tr class="heading"><td colspan="2"><h2 class="groupheader"><a id="func-members" name="func-members"></a>
Functions</h2></td></tr>
<tr class="memitem:a4b76571a2a04fa99c30a96eca9997f0e" id="r_a4b76571a2a04fa99c30a96eca9997f0e"><td class="memItemLeft" align="right" valign="top">uint64_t&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="#a4b76571a2a04fa99c30a96eca9997f0e">next_higher_number</a> (uint64_t x)</td></tr>
<tr class="memdesc:a4b76571a2a04fa99c30a96eca9997f0e"><td class="mdescLeft">&#160;</td><td class="mdescRight">The main function implements checking the next number. <br /></td></tr>
<tr class="separator:a4b76571a2a04fa99c30a96eca9997f0e"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:a5032470c9974bbd6ec254bf296530a5f" id="r_a5032470c9974bbd6ec254bf296530a5f"><td class="memItemLeft" align="right" valign="top">bool&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="#a5032470c9974bbd6ec254bf296530a5f">isPowerOfTwo</a> (std ::int64_t n)</td></tr>
<tr class="memdesc:a5032470c9974bbd6ec254bf296530a5f"><td class="mdescLeft">&#160;</td><td class="mdescRight">The main function implements check for power of 2. <br /></td></tr>
<tr class="separator:a5032470c9974bbd6ec254bf296530a5f"><td class="memSeparator" colspan="2">&#160;</td></tr>
</table>
<a name="details" id="details"></a><h2 class="groupheader">Detailed Description</h2>
<div class="textblock"><p>for IO operations </p>
<p>Bit manipulation algorithms.</p>
<p>for io operations</p>
<p>storing the numbers</p>
<p>for assert</p>
<p>Bit manipulation algorithms</p>
<p>for assert for IO operations</p>
<p>Bit manipulation algorithms</p>
<p>for assert</p>
<p>Bit Manipulation algorithms</p>
<p>for <a class="elRef" target="_blank" href="http://en.cppreference.com/w/cpp/algorithm/min.html">std::min</a> for assert for IO operations for limits of integral types for <a class="elRef" target="_blank" href="http://en.cppreference.com/w/cpp/container/vector.html">std::vector</a> </p>
</div><h2 class="groupheader">Function Documentation</h2>
<a id="a5032470c9974bbd6ec254bf296530a5f" name="a5032470c9974bbd6ec254bf296530a5f"></a>
<h2 class="memtitle"><span class="permalink"><a href="#a5032470c9974bbd6ec254bf296530a5f">&#9670;&#160;</a></span>isPowerOfTwo()</h2>
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<td class="memname">bool bit_manipulation::isPowerOfTwo </td>
<td>(</td>
<td class="paramtype">std ::int64_t</td> <td class="paramname"><span class="paramname"><em>n</em></span></td><td>)</td>
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<p>The main function implements check for power of 2. </p>
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">n</td><td>is the number who will be checked </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>either true or false </dd></dl>
<div class="fragment"><div class="line"><span class="lineno"> 31</span> { <span class="comment">// int64_t is preferred over int so that</span></div>
<div class="line"><span class="lineno"> 32</span> <span class="comment">// no Overflow can be there.</span></div>
<div class="line"><span class="lineno"> 33</span> </div>
<div class="line"><span class="lineno"> 34</span> <span class="keywordflow">return</span> n &gt; 0 &amp;&amp; !(n &amp; n - 1); <span class="comment">// If we subtract a power of 2 numbers by 1</span></div>
<div class="line"><span class="lineno"> 35</span> <span class="comment">// then all unset bits after the only set bit become set; and the set bit</span></div>
<div class="line"><span class="lineno"> 36</span> <span class="comment">// becomes unset.</span></div>
<div class="line"><span class="lineno"> 37</span> </div>
<div class="line"><span class="lineno"> 38</span> <span class="comment">// If a number n is a power of 2 then bitwise and of n-1 and n will be zero.</span></div>
<div class="line"><span class="lineno"> 39</span> <span class="comment">// The expression n&amp;(n-1) will not work when n is 0.</span></div>
<div class="line"><span class="lineno"> 40</span> <span class="comment">// To handle this case also, our expression will become n&amp; (!n&amp;(n-1))</span></div>
<div class="line"><span class="lineno"> 41</span>}</div>
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<a id="a4b76571a2a04fa99c30a96eca9997f0e" name="a4b76571a2a04fa99c30a96eca9997f0e"></a>
<h2 class="memtitle"><span class="permalink"><a href="#a4b76571a2a04fa99c30a96eca9997f0e">&#9670;&#160;</a></span>next_higher_number()</h2>
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<td class="memname">uint64_t bit_manipulation::next_higher_number </td>
<td>(</td>
<td class="paramtype">uint64_t</td> <td class="paramname"><span class="paramname"><em>x</em></span></td><td>)</td>
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<p>The main function implements checking the next number. </p>
<dl class="params"><dt>Parameters</dt><dd>
<table class="params">
<tr><td class="paramname">x</td><td>the number that will be calculated </td></tr>
</table>
</dd>
</dl>
<dl class="section return"><dt>Returns</dt><dd>a number </dd></dl>
<div class="fragment"><div class="line"><span class="lineno"> 32</span> {</div>
<div class="line"><span class="lineno"> 33</span> uint64_t rightOne = 0;</div>
<div class="line"><span class="lineno"> 34</span> uint64_t nextHigherOneBit = 0;</div>
<div class="line"><span class="lineno"> 35</span> uint64_t rightOnesPattern = 0;</div>
<div class="line"><span class="lineno"> 36</span> </div>
<div class="line"><span class="lineno"> 37</span> uint64_t next = 0;</div>
<div class="line"><span class="lineno"> 38</span> </div>
<div class="line"><span class="lineno"> 39</span> <span class="keywordflow">if</span> (x) {</div>
<div class="line"><span class="lineno"> 40</span> <span class="comment">// right most set bit</span></div>
<div class="line"><span class="lineno"> 41</span> rightOne = x &amp; -<span class="keyword">static_cast&lt;</span><span class="keywordtype">signed</span><span class="keyword">&gt;</span>(x);</div>
<div class="line"><span class="lineno"> 42</span> </div>
<div class="line"><span class="lineno"> 43</span> <span class="comment">// reset the pattern and set next higher bit</span></div>
<div class="line"><span class="lineno"> 44</span> <span class="comment">// left part of x will be here</span></div>
<div class="line"><span class="lineno"> 45</span> nextHigherOneBit = x + rightOne;</div>
<div class="line"><span class="lineno"> 46</span> </div>
<div class="line"><span class="lineno"> 47</span> <span class="comment">// nextHigherOneBit is now part [D] of the above explanation.</span></div>
<div class="line"><span class="lineno"> 48</span> </div>
<div class="line"><span class="lineno"> 49</span> <span class="comment">// isolate the pattern</span></div>
<div class="line"><span class="lineno"> 50</span> rightOnesPattern = x ^ nextHigherOneBit;</div>
<div class="line"><span class="lineno"> 51</span> </div>
<div class="line"><span class="lineno"> 52</span> <span class="comment">// right adjust pattern</span></div>
<div class="line"><span class="lineno"> 53</span> rightOnesPattern = (rightOnesPattern) / rightOne;</div>
<div class="line"><span class="lineno"> 54</span> </div>
<div class="line"><span class="lineno"> 55</span> <span class="comment">// correction factor</span></div>
<div class="line"><span class="lineno"> 56</span> rightOnesPattern &gt;&gt;= 2;</div>
<div class="line"><span class="lineno"> 57</span> </div>
<div class="line"><span class="lineno"> 58</span> <span class="comment">// rightOnesPattern is now part [A] of the above explanation.</span></div>
<div class="line"><span class="lineno"> 59</span> </div>
<div class="line"><span class="lineno"> 60</span> <span class="comment">// integrate new pattern (Add [D] and [A])</span></div>
<div class="line"><span class="lineno"> 61</span> next = nextHigherOneBit | rightOnesPattern;</div>
<div class="line"><span class="lineno"> 62</span> }</div>
<div class="line"><span class="lineno"> 63</span> </div>
<div class="line"><span class="lineno"> 64</span> <span class="keywordflow">return</span> next;</div>
<div class="line"><span class="lineno"> 65</span>}</div>
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