Find total number of Rectangles (excluding squares) in a N*N chessboard.
Input:N = 1Output:0Explanation:There is only 1 square on a 1*1 chess
board. There are no Proper Rectangles.
Input:N = 2Output:4Explanation:There are 4 rectangles in a 2*2 chessboard.
You don't need to read input or print anything. Your task is to complete the function rectanglesInChessBoard() which takes an Integer N as input and returns the number of rectangles in a N*N chess board.
Expected Time Complexity: O(1) Expected Auxiliary Space: O(1)