HDU 1838 Chessboard

dp[i][j]表示以（i,j）為右下角所含棋盤的最大規模，

如果 s[i][j] == s[i-1][j-1] && s[i][j] != s[i-1][j] && s[i][j] != s[i][j-1]      dp[i][j] = min( dp[i-1][j-1], dp[i-1][j], dp[i][j-1]) + 1

否則dp[i][j] = 1

1 //#define LOCAL
 2 #include <iostream>
 3 #include <cstdio>
 4 #include <cstring>
 5 #include <algorithm>
 6 using namespace std;
 7 
 8 int const maxn = 2000 + 5;
 9 char map[maxn][maxn];
10 int dp[maxn][maxn];
11 
12 int main(void)
13 {
14     #ifdef LOCAL
15         freopen("1838in.txt", "r", stdin);
16     #endif
17 
18     int T;
19     scanf("%d", &T);
20     while(T--)
21     {
22         int n;
23         scanf("%d", &n);
24         int i, j;
25         for(i = 0; i < n; ++i)
26             scanf("%s", map[i]);
27         for(i = 0; i < n; ++i)
28             dp[0][i] = dp[i][0] = 1;
29         int size = 1, cnt = 0;
30         for(i = 1; i < n; ++i)
31             for(j = 1; j < n; ++j)
32             {
33                 if(map[i][j] == map[i-1][j-1] && map[i][j] != map[i-1][j] 
34                     && map[i][j] != map[i][j-1])
35                     dp[i][j] = min(min(dp[i][j-1], dp[i-1][j]), dp[i-1][j-1]) + 1;
36                 else dp[i][j] = 1;
37                 if(map[i][j] == '1')
38                     size = max(size, dp[i][j]);
39             }
40 
41         for(i = 0; i < n; ++i)
42             for(j = 0; j < n; ++j)
43                 if(dp[i][j] == size && map[i][j] == '1')
44                     ++cnt;
45         printf("%d %d\n", size, cnt);
46     }
47     return 0;
48 }      

代碼君