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1074. Number of Submatrices That Sum to Target

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Description

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

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

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'.

 

Example 1:

Input: matrix = [[0,1,0],[1,1,1],[0,1,0]], target = 0

Output: 4

Explanation: The four 1x1 submatrices that only contain 0.

Example 2:

Input: matrix = [[1,-1],[-1,1]], target = 0

Output: 5

Explanation: The two 1x2 submatrices, plus the two 2x1 submatrices, plus the 2x2 submatrix.

 

Note:

<li><code>1 &lt;= matrix.length &lt;= 300</code></li>

<li><code>1 &lt;= matrix[0].length &lt;= 300</code></li>

<li><code>-1000 &lt;= matrix[i] &lt;= 1000</code></li>

<li><code>-10^8 &lt;= target &lt;= 10^8</code></li>

Solutions

Python3

Java

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