HDU 1838 Chessboard

dp[i][j]表示以（i,j）为右下角所含棋盘的最大规模，

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

否则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 }

代码君