#919 · #2013 · Detect Squares(检测正方形)

Design a class that stores points on the X-Y plane and answers, for a query point, how many axis-aligned squares can be formed using the query point and three previously added points. Duplicate points are allowed and count separately. Constraints: 1 <= point.length == 2, 0 <= xi, yi <= 1000, at most 5000 calls to add and count.