144. Count Rectangles with All Ones

Given a binary matrix, return the number of submatrices (rectangles) that contain only 1s. Input: JSON 2D grid of 0/1.

Input: A JSON 2D 0/1 grid.

Output: Integer — count of all-ones submatrices.

Examples

Example 1

Input: [[1,0,1],[1,1,0],[1,1,0]]
Output: 13
Explanation: 13 all-ones submatrices.

Example 2

Input: [[1]]
Output: 1
Explanation: Single 1.

Example 3

Input: [[0]]
Output: 0
Explanation: No ones.