You are given a stream of points on the X-Y plane. Design an algorithm that:
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 with an empty data structure.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.
Example 1:
Input ["DetectSquares", "add", "add", "add", "count", "count", "add", "count"] [[], [[3, 10]], [[11, 2]], [[3, 2]], [[11, 10]], [[14, 8]], [[11, 2]], [[11, 10]]] Output [null, null, null, null, 1, 0, null, 2] Explanation DetectSquares detectSquares = new DetectSquares(); detectSquares.add([3, 10]); detectSquares.add([11, 2]); detectSquares.add([3, 2]); detectSquares.count([11, 10]); // return 1. You can choose: // - The first, second, and third points detectSquares.count([14, 8]); // return 0. The query point cannot form a square with any points in the data structure. detectSquares.add([11, 2]); // Adding duplicate points is allowed. detectSquares.count([11, 10]); // return 2. You can choose: // - The first, second, and third points // - The first, third, and fourth points
Constraints:
point.length == 2
0 <= x, y <= 1000
3000
calls in total will be made to add
and count
.