This problem is adapted from Count the Number of Squares at Wolfram Challenges, so you might want to first check out that page for illustrative visualizations of this problem.

Given a sequence of points (coordinates x, y as nonnegative integers), your function should count how many squares exist so that all four corners are members of points. Note that these squares are not required to be axis-aligned so that their sides would have to be either horizontal and vertical. For example, the points [0, 3], [3, 0], [6, 3], [3, 6] define a square, even if it may happen to look like a lozenge from our axis-aligned vantage point.

By the way, if your want to try another approach and count squares, having lines between points, The Square Chest awaits you!

Input: Array of tuples of two integers (number).

Output: Integer (number).

Examples:

assert.strictEqual(
    countSquares([
        [0, 0],
        [1, 0],
        [0, 1],
        [1, 1],
    ]),
    1
);
assert.strictEqual(
    countSquares([
        [0, 0],
        [1, 0],
        [2, 0],
        [0, 1],
        [1, 1],
        [2, 1],
        [0, 2],
        [1, 2],
        [2, 2],
    ]),
    6
);
assert.strictEqual(
    countSquares([
        [4, 3],
        [1, 1],
        [5, 3],
        [2, 3],
        [3, 2],
        [3, 1],
        [4, 2],
        [2, 1],
        [3, 3],
        [1, 2],
        [5, 2],
    ]),
    3
);

The mission was taken from Python CCPS 109. It is taught for Ryerson Chang School of Continuing Education by Ilkka Kokkarinen