title: What is the most efficient algorithm to find a straight line that goes through most points?
body: <p>The problem:</p>
  
  <p>N points are given on a 2-dimensional plane. What is the maximum number of points on the same <em>straight</em> line?</p>
  
  <p>The problem has O(N<sup>2</sup>) solution: go through each point and find the number of points which have the same <code>dx / dy</code> with relation to the current point. Store <code>dx / dy</code> relations in a hash map for efficiency.</p>
  
  <p>Is there a better solution to this problem than O(N<sup>2</sup>)?</p>