URAL 1146 Maximum Sum（最大子矩阵的和 DP）

 1 int n, m, x, y, T, t;
 2 int Map[1010][1010];
 3 
 4 int main()
 5 {
 6     while(~scanf("%d", &n))
 7     {
 8         memset(Map, 0, sizeof(Map));
 9         for(int i = 1; i <= n; ++i)
10         {
11             for(int j = 1; j <= n; ++j)
12             {
13                 scanf("%d", &t);
14                 Map[i][j] = Map[i-1][j]+t;
15             }
16         }
17         int Max = -INF;
18         for(int i = 1; i <= n; ++i)
19         {
20             for(int j = i; j <= n; ++j)
21             {
22                 int sum = 0;
23                 for(int k = 1; k <= n; ++k)
24                 {
25                     sum = sum<0?0:sum;
26                     sum += Map[j][k]-Map[i-1][k];
27                     Max = max(sum, Max);
28                 }
29             }
30         }
31         printf("%d\n", Max);
32     }
33 
34 
35     return 0;
36 }