Leetcode 3025. Find the Number of Ways to Place People I

Count the number of ordered pairs (A,B) of distinct points where A is strictly to the left and above B (A.x < B.x and A.y > B.y) and the axis-aligned rectangle spanned by A and B (including its border) contains no other points. With n ≤ 50 and integer coordinates, this reduces to checking pairwise dominance and emptiness of the rectangle between them.