poj3009Curling 2.0（dfs)

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 1 #include <iostream>

 2 #include<cstdio>

 3 #include<cstring>

 4 using namespace std;

 5 int board[110][110];

 6 int di,dj,xi,xj,n,m,num,dis[4][2] = {0,1,0,-1,1,0,-1,0};

 7 void dfs(int v,int x,int y)

 8 {

 9     int i,tx,ty,flag = 0;

10     if(v>10)

11     return ;

12     for(i = 0 ; i < 4 ; i++)

13     {

14         tx = x;

15         ty = y;

16         flag = 0;

17         if(board[x+dis[i][0]][y+dis[i][1]]==1)

18         continue;

19         while(1)

20         {

21             tx = tx+dis[i][0];

22             ty = ty+dis[i][1];

23             if(tx<0||tx>n||ty<0||ty>m)

24             break;

25             if(board[tx][ty]==3)

26             {

27                 if(num>v)

28                 num = v;

29                 break;

30             }

31             if(board[tx][ty]==1)

32             {

33                 flag = 1;

34                 break;

35             }

36         }

37         if(flag)

38         {

39             board[tx][ty] = 0;

40             dfs(v+1,tx-dis[i][0],ty-dis[i][1]);

41             board[tx][ty] = 1;

42         }

43     }

44 }

45 int main()

46 {

47     int i,j;

48     while(cin>>m>>n)

49     {

50         if(m==0&&n==0)

51         break;

52         num = 15;

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

54         for(j = 1; j <= m ; j++)

55         {

56             cin>>board[i][j];

57             if(board[i][j]==2)

58             {

59                 xi = i;

60                 xj = j;

61             }

62             if(board[i][j]==3)

63             {

64                 di = i;

65                 dj = j;

66             }

67         }

68         dfs(1,xi,xj);

69         if(num>10)

70         cout<<"-1\n";

71         else

72         cout<<num<<endl;

73     }

74     return 0;

75 }

 

http://poj.org/problem?id=3009

求最短 直接就用了BFS 结果ME 后有看了人家写的dfs 写了一份dfs 更新最小值

 

View Code

  1 #include <iostream>

  2 #include<cstdio>

  3 #include<cstring>

  4 using namespace std;

  5 char s[50][50],so[2];

  6 int pr[5],dis[4][2]={-1,0,0,-1,1,0,0,1},vis[50][50],n,m,flag;

  7 int dir[2][4][4] = {{{1, 0, 3, 2}, {2, 1, 0, 3}, {3, 2, 1, 0}, {0, 3, 2, 1}},{{3, 0, 1, 2}, {0, 1, 2, 3}, {1, 2, 3, 0}, {2, 3, 0, 1}}};

  8 struct node

  9 {

 10     int x,y,num;

 11 }q[100010];

 12 int judge(int x,int y)

 13 {

 14     if(x<1||x>n||y<1||y>m)

 15     return 0;

 16     if(s[x][y]=='#')

 17     return 0;

 18     return 1;

 19 }

 20 void bfs()

 21 {

 22     int i,j,p = 0, d = 1;

 23     memset(vis,0,sizeof(vis));

 24     q[d].x = so[0];

 25     q[d].y = so[1];

 26     q[d].num = 1;

 27     while(p!=d)

 28     {

 29         p++;

 30         int tx = q[p].x;

 31         int ty = q[p].y;

 32         int tnum = q[p].num;

 33         if(s[tx][ty]=='E')

 34         {

 35             pr[2] = tnum;

 36             break;

 37         }

 38         for(i = 0 ; i < 4 ; i++)

 39         {

 40             int nx = tx+dis[i][0];

 41             int ny = ty+dis[i][1];

 42             if(!vis[nx][ny]&&judge(nx,ny))

 43             {

 44                 vis[nx][ny] = 1;

 45                 d++;

 46                 q[d].x = nx;

 47                 q[d].y = ny;

 48                 q[d].num = tnum+1;

 49             }

 50         }

 51     }

 52 }

 53 void dfs(int x,int y,int d,int f)

 54 {

 55     pr[f]++;

 56     if(s[x][y]=='E')

 57         return ;

 58     int i,j;

 59     if(f==1)

 60     cout<<x<<" "<<y<<endl;

 61     for(j = 0 ; j < 4 ; j++)

 62     {

 63         int td = dir[f][d][j];

 64         int tx = x+dis[td][0];

 65         int ty = y+dis[td][1];

 66         if(!vis[tx][ty]&&judge(tx,ty))

 67         {

 68               vis[tx][ty] = 1;

 69               dfs(tx,ty,td,f);

 70         }

 71     }

 72 }

 73 int main()

 74 {

 75     int i,j,k,t,in;

 76     cin>>t;

 77     while(t--)

 78     {

 79         cin>>m>>n;

 80         pr[0] = 1;

 81         pr[1] = 1;

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

 83         {

 84             getchar();

 85             for(j = 1 ; j <= m ; j++)

 86             {

 87                 cin>>s[i][j];

 88                 if(s[i][j]=='S')

 89                 {

 90                     so[0] = i;

 91                     so[1] = j;

 92                     if(so[0]==n)

 93                     in = 0;

 94                     if(so[0]==1)

 95                     in = 2;

 96                     if(so[1]==m)

 97                     in = 1;

 98                     if(so[1]==1)

 99                     in = 3;

100                 }

101             }

102         }

103         bfs();

104         for(i = 0 ; i < 2 ; i++)

105         {

106             memset(vis,0,sizeof(vis));

107             vis[so[0]+dis[in][0]][so[1]+dis[in][1]] = 1;

108             dfs(so[0]+dis[in][0],so[1]+dis[in][1],in,i);

109         }

110         cout<<pr[0]<<" "<<pr[1]<<" "<<pr[2]<<endl;

111     }

112     return 0;

113 }