Vijos 1143 三取方格数(DP)

题目链接

传纸条的加强版，会了那个，这个也就没问题了。数据范围特别小。6维的也能过吧。。。

 1 #include <stdio.h>

 2 #include <string.h>

 3 int p[21][21],o[61][21][21][21];

 4 int main()

 5 {

 6     int i,j,k,u,n,max,t;

 7     int a[9] = {0,0,0,-1,-1,-1,0,-1};

 8     int b[9] = {0,0,-1,0,-1,0,-1,-1};

 9     int c[9] = {0,-1,0,0,0,-1,-1,-1};

10     scanf("%d",&n);

11     for(i = 1; i <= n; i ++)

12         for(j = 1; j <= n; j ++)

13         {

14             scanf("%d",&p[i][j]);

15         }

16     memset(o,243,sizeof(o));

17     o[0][1][1][1] = p[1][1];

18     for(i = 1; i <= 2*n-2; i ++)

19     {

20         for(j = 1; j <= n&&j <= i+1; j ++)

21         {

22             for(k = 1; k <= n&&k <= i+1; k ++)

23             {

24                 for(u = 1; u <= n&&u <= i+1; u ++)

25                 {

26                     for(t = 0; t <= 7; t ++)

27                     {

28                         if(t == 0)

29                             max = o[i-1][j+a[t]][k+b[t]][u+c[t]];

30                         else

31                         {

32                             if(max < o[i-1][j+a[t]][k+b[t]][u+c[t]])

33                                 max = o[i-1][j+a[t]][k+b[t]][u+c[t]];

34                         }

35                     }

36                     if(k == j)

37                         max += p[j][i+2-j];

38                     else

39                         max += p[j][i+2-j]+p[k][i+2-k];

40                     if(j != u&&k != u)

41                         max += p[u][i+2-u];

42                     o[i][j][k][u] = max;

43                 }

44             }

45         }

46     }

47     printf("%d\n",o[2*n-2][n][n][n]);

48     return 0;

49 }