title: C++ Adding 2 arrays together quickly
body: <p>Given the arrays:</p>
  
  <pre><code>int canvas[10][10];
  int addon[10][10];
  </code></pre>
  
  <p>Where all the values range from 0 - 100, <strong>what is the fastest way in C++ to add those two arrays so each cell in canvas equals itself plus the corresponding cell value in addon?</strong></p>
  
  <p>IE, I want to achieve something like:</p>
  
  <pre><code>canvas += another;
  </code></pre>
  
  <p>So if canvas[0][0] =3 and addon[0][0] = 2 then canvas[0][0] = 5</p>
  
  <p>Speed is essential here as I am writing a very simple program to brute force a knapsack type problem and there will be tens of millions of combinations.</p>
  
  <p>And as a small extra question (thanks if you can help!) <strong>what would be the fastest way of checking if any of the values in canvas exceed 100?</strong>  Loops are slow!</p>