356. Detect Squares

You are given a stream of points on the X-Y plane. Design an algorithm that: - Adds new points from the stream into a data structure. Duplicate points are allowed and should be treated as different points. - Given a query point, counts the number of ways to choose three points from the data structure such that the three points and the query point form an axis-aligned square with positive area. An axis-aligned square is a square whose edges are all the same length and are either parallel or perpendicular to the x-axis and y-axis. Implement the DetectSquares class: - DetectSquares() Initializes the object. - void add(int[] point) Adds a new point point = [x, y] to the data structure. - int count(int[] point) Counts the number of ways to form axis-aligned squares with point point = [x, y] as described above.