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POCan I optimize code that has 3 for loops and 4 ifs?
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  1. POCan I optimize code that has 3 for loops and 4 ifs?
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    copied!<p>i made another post</p> <p><a href="https://stackoverflow.com/questions/326885/a-loop-to-create-neighbor-nodes-in-3d-space">here</a> where I asked how to create the 26 neighbors of a cubic-voxel-node in 3-d space. I got a very good answer and implemented it. </p> <p>To that I added some MIN MAX Position checking.</p> <p>I would like to know if there is way, <strong>in relationship to the 3 for loops and 4 if used</strong>, to improve the execution time of this code. I have read in another post sth that when using while loops is faster but it was in a post not language specific. </p> <p>Is this true? If yes, could u please help me to this in my code because i luck experience? Is there a way to implement this recursively in a way that will make it faster?</p> <p>here is my code:</p> <pre><code>... std::vector&lt;Pos&gt; Create26Neighbor(Pos somePos, double resol) { std::vector &lt;Pos&gt; vect1; Pos m_MinPos(0.0,0.0,0.0); Pos m_MaxPos(5.0,4.0,5.0); for (double dz = somePos.m_pPos[2] - resol; dz &lt;= somePos.m_pPos[2] + resol; dz+=resol) { if (dz&gt;m_MinPos.m_pPos[2] &amp;&amp; dz&lt;m_MaxPos.m_pPos[2]) { for (double dy = someCPos.m_pPos[1] - resol; dy &lt;= someCPos.m_pPos[1] + resol; dy+=resol) { if (dy&gt;m_MinPos.m_pPos[1] &amp;&amp; dy&lt;m_MaxPos.m_pPos[1]) { for (double dx = somePos.m_pPos[0] - resol; dx &lt;= somePos.m_pPos[0] + resol; dx+=resol) { if (dx&gt;m_MinPos.m_pPos[0] &amp;&amp; dx&lt;m_MaxPos.m_pPos[0]) { // all 27 if ((dx != somePos.m_pPos[0]) || (dy != somePos.m_pPos[1]) || (dz != somePos.m_pPos[2])) { Pos tempPos(dx,dy,dz); vect1.push_back(tempPos); } } } } } } } return vect1; } .... </code></pre>
 

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