-
Notifications
You must be signed in to change notification settings - Fork 1
/
P1736.c
53 lines (49 loc) · 1.48 KB
/
P1736.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
#include "stdio.h"
#include "stdlib.h"
#include "string.h"
#define maxn 2500
int matrix[maxn][maxn];
int dp[maxn][maxn];
int h[maxn][maxn];
int v[maxn][maxn];
int min(int a, int b) {
return a < b ? a : b;
}
int main() {
int n, m, res = 0;
scanf("%d %d", &n, &m);
for (int i = 0; i < n; i++)
for (int j = 0; j < m; j++)
scanf("%d", &matrix[i][j]);
dp[0][0] = matrix[0][0];
for (int i = 0; i < n; i++)
for (int j = 0; j < m; j++) {
if (!matrix[i][j]) {
h[i][j] = j ? h[i][j - 1] + 1 : 1;
v[i][j] = i ? v[i - 1][j] + 1 : 1;
}
else {
if (i - 1 >= 0 && j - 1 >= 0) dp[i][j] = min(dp[i - 1][j - 1], min(h[i][j - 1], v[i - 1][j])) + 1;
else dp[i][j] = 1;
}
if (dp[i][j] > res) res = dp[i][j];
}
memset(dp, 0, sizeof(dp));
memset(h, 0, sizeof(h));
memset(v, 0, sizeof(v));
dp[0][m - 1] = matrix[0][m - 1];
for (int i = 0; i < n; i++)
for (int j = m - 1; j >= 0; j--) {
if (!matrix[i][j]) {
h[i][j] = j + 1 < m ? h[i][j + 1] + 1 : 1;
v[i][j] = i ? v[i - 1][j] + 1 : 1;
}
else {
if (i - 1 >= 0 && j + 1 < m) dp[i][j] = min(dp[i - 1][j + 1], min(h[i][j + 1], v[i - 1][j])) + 1;
else dp[i][j] = 1;
}
if (dp[i][j] > res) res = dp[i][j];
}
printf("%d\n", res);
return 0;
}