Count Square Submatrices with All Ones
Medium
You receive a m * n matrix of ones and zeros, provide 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:
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There are 10 squares of side 1.
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There are 4 squares of side 2.
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There is 1 square of side 3.
Total count of squares = 10 + 4 + 1 = 15.
Example 2
Input: matrix = [ [1,0,1], [1,1,0], [1,1,0] ]
Output: 7
Explanation:
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There are 6 squares of side 1.
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There is 1 square of side 2.
Total count of squares = 6 + 1 = 7.
Constraints
1 <= matrix.length <= 3001 <= matrix[0].length <= 3000 <= matrix[i][j] <= 1
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