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// 1504. Count Submatrices With All Ones
#include "leetcode.h"
/*
* given an 'm x n' binary matrix 'mat', return the number of submatrices that
* have all ones.
*/
int numSubmat(int **mat, int matSize, int *matColSize) {
int m = matColSize[0], ans = 0;
int *dp = (int *)calloc(m, sizeof(int));
for (int i = 0; i < matSize; i++) {
for (int j = 0; j < m; j++)
dp[j] = mat[i][j] ? dp[j] + 1 : 0;
int *sum = (int *)calloc(m, sizeof(int));
int *stack = (int *)malloc(m * sizeof(int)), top = -1;
for (int j = 0; j < m; j++) {
while (top >= 0 && dp[stack[top]] >= dp[j])
top--;
if (top >= 0) {
int curr = stack[top];
sum[j] = sum[curr] + dp[j] * (j - curr);
} else
sum[j] = dp[j] * (j + 1);
stack[++top] = j;
ans += sum[j];
}
free(sum), free(stack);
}
free(dp);
return ans;
}
int main() {
int m1i[3][3] = {{1, 0, 1}, {1, 1, 0}, {1, 1, 0}},
m2i[3][4] = {{0, 1, 1, 0}, {0, 1, 1, 1}, {1, 1, 1, 0}};
struct two_d_arr *m1 =
two_d_arr_init(ARRAY_SIZE(m1i), ARRAY_SIZE(m1i[0]), m1i);
struct two_d_arr *m2 =
two_d_arr_init(ARRAY_SIZE(m2i), ARRAY_SIZE(m2i[0]), m2i);
printf("%d\n", numSubmat(m1->arr, m1->row_size, m1->col_size)); // expect: 13
printf("%d\n", numSubmat(m2->arr, m2->row_size, m2->col_size)); // expect: 24
two_d_arr_free(m1);
two_d_arr_free(m2);
}
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