message: Update count-lattice-points-inside-a-circle.cpp
diff: // Time: O(n * r^2)
  // Space: O(min(n * r^2, max_x * max_y))
  -// math, set
  +// math, hash table
  class Solution {
  public:
  int countLatticePoints(vector<vector<int>>& circles) {
  