{ "data": { "question": { "questionId": "1145", "questionFrontendId": "1074", "boundTopicId": null, "title": "Number of Submatrices That Sum to Target", "titleSlug": "number-of-submatrices-that-sum-to-target", "content": "

Given a matrix and a target, return the number of non-empty submatrices that sum to target.

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A submatrix x1, y1, x2, y2 is the set of all cells matrix[x][y] with x1 <= x <= x2 and y1 <= y <= y2.

\n\n

Two submatrices (x1, y1, x2, y2) and (x1', y1', x2', y2') are different if they have some coordinate that is different: for example, if x1 != x1'.

\n\n

 

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Example 1:

\n\"\"\n
\nInput: matrix = [[0,1,0],[1,1,1],[0,1,0]], target = 0\nOutput: 4\nExplanation: The four 1x1 submatrices that only contain 0.\n
\n\n

Example 2:

\n\n
\nInput: matrix = [[1,-1],[-1,1]], target = 0\nOutput: 5\nExplanation: The two 1x2 submatrices, plus the two 2x1 submatrices, plus the 2x2 submatrix.\n
\n\n

Example 3:

\n\n
\nInput: matrix = [[904]], target = 0\nOutput: 0\n
\n\n

 

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Constraints:

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