Technical interview question:
Given a 2D array A (M rows, N columns) of integers, find if any four elements of A with value V are at the corners of a rectangle.

Example:

Given

A = [[7, 9, 7, 1, 7, 2],

    [8, 1, 0, 2, 1, 1],

    [7, 0, 1, 0, 7, 3],

    [1, 1, 6, 1, 1, 8],

    [5, 2, 9, 7, 1, 7],]

When V = 1, return true

When V = 7, return true

When V = 6, return false

Inputs are: A, V
Output: Boolean