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+// 1074. Number of Submatrices That Sum to Target
+#include "leetcode.h"
+
+/*
+ * given a 'matrix' and '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 are
+ * different if they have some coordinate that is different. for example if x1
+ * != x1
+ */
+
+int numSubmatrixSumTarget(int **matrix, int matrix_size, int *matrix_col_size,
+ int target) {
+ int r_size = matrix_col_size[0], dp[r_size], ans = 0, y = 0;
+ while (y < matrix_size) {
+ memset(dp, 0, sizeof(int) * r_size);
+ for (int row = y; row < matrix_size; row++)
+ for (int col = 0; col < r_size; col++)
+ dp[col] += matrix[row][col];
+ for (int col = 0; col < r_size; col++) {
+ int sum = 0;
+ for (int _col = col; _col < r_size; _col++) {
+ sum += dp[_col];
+ if (sum == target)
+ ans++;
+ }
+ }
+ y++;
+ }
+ return ans;
+}