Counting Square Submatrices With All Ones In O(m*n) Time Complexity

1277. Count Square Submatrices with All Ones
Difficulty: Medium
Topics: Array, Dynamic Programming, Matrix
Given a m * n matrix of ones and zeros, return how many square submatrices have all ones.
Example 1:

Input: matrix = [[0,1,1,1], [1,1,1,1], [0,1,1,1]]
Output: 15
Explanation:

There are 10 squares of side 1.
There are 4 squares of side 2.
There is  1 square of side 3.
Total number of squares = 10 + 4 + 1 = 15.



Example 2:

Input: matrix = [[1,0,1], [1,1,0], [1,1,0]]
Output: 7
Explanation:

There are 6 squares of side 1.
There is 1 square of side 2.
Total number of squares = 6 + 1 = 7....