title: find overlapping rectangles algorithm
body: <p>let's say I have a huge set of non-overlapping rectangle with integer coordinates, who are fixed once and for all</p>
  
  <p>I have another rectangle A with integer coordinates whose coordinates are moving (but you can assume that its size is constant)</p>
  
  <p>What is the most efficient way to find which rectangles are intersecting (or inside) A?
  I cannot simply loop through my set as it is too big. Thanks</p>
  
  <p>edit : the rectangles are all parallel to the axis</p>