TC SRM 593 DIV1 250(dfs)

这图最多3色就可以 搜2就行了 

 1 #include <iostream>

 2 #include<cstdio>

 3 #include<cstring>

 4 #include<stdlib.h>

 5 #include<vector>

 6 #include<algorithm>

 7 #include<string>

 8 using namespace std;

 9 int vis[55][55],c[55][55],f[10],mm;

10 int dis[6][2] = {{1,0},{0,1},{-1,0},{0,-1},{-1,1},{1,-1}},n;

11 int flag,m;

12 int judge(int x,int y)

13 {

14     if(x<0||y<0||x>=n||y>=n)

15     return 0;

16     return 1;

17 }

18 int dfs(int x,int y,vector <string> board,int o)

19 {

20     int i;

21     for(i = 0 ; i < 6 ; i++)

22     {

23         int tx = x+dis[i][0];

24         int ty = y+dis[i][1];

25         if(judge(tx,ty)&&board[tx][ty]=='X')

26         {

27             if(c[tx][ty])

28             {

29                 if(c[tx][ty]!=o)

30                 return 0;

31             }

32             else

33             {

34                 flag = 1;

35                 c[tx][ty] = o;

36                 if(!dfs(tx,ty,board,-o))

37                 return 0;

38             }

39         }

40     }

41     return 1;

42 }

43 class HexagonalBoard

44 {

45     public:

46     int minColors(vector <string> board)

47     {

48         int i,j,k = board.size();

49         n = k;

50         int ff = 1;

51         for(i = 0 ; i < n ; i++)

52         {

53             for(j = 0 ; j < n ; j++)

54             {

55                 if(board[i][j]=='X'&&!c[i][j])

56                 {

57                     m++;

58                     c[i][j] = 1;

59                     if(!dfs(i,j,board,-1))

60                     {

61                         ff=0;

62                         break;

63                     }

64                 }

65             }

66             if(!ff) break;

67         }

68         if(!m) return 0;

69         if(!flag)

70         return 1;

71         if(ff)

72         return 2;

73         else

74         return 3;

75     }

76 };

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