胜利大逃亡(续)(bfs)

http://acm.hdu.edu.cn/showproblem.php?pid=1429

 #include <stdio.h>
 #include <queue>
 #include <string.h>
 using namespace std;
 struct node
 {
     int x,y;
     int state;
     int step;
 } s,t;
 int Time,n,m;
 int s_x,s_y,e_x,e_y;
 char a[][];
 int vis[][][];//标记状态
 int dir[][] = {{,},{-,},{,-},{,}};
 void bfs()
 {
     memset(vis,,sizeof(vis));
     queue<node>q;
     s.x = s_x;
     s.y = s_y;
     s.state = ;
     s.step = ;
     q.push(s);
     vis[s_x][s_y][s.state] = ;
     while(!q.empty())
     {
         t = q.front();
         q.pop();
         int x = t.x;
         int y = t.y;
         if (x==e_x&&y==e_y)
         {
             Time = t.step;
             return ;
         }
         for (int i = ; i < ; i++)
         {
             int dx = x+dir[i][];
             int dy = y+dir[i][];

             if (dx>=&&dx<n && dy>=&&dy<m && (!vis[dx][dy][t.state]) && a[dx][dy]!='*')
             {
                 if (a[dx][dy]=='.'||a[dx][dy]=='^'||a[dx][dy]=='@')
                 {
                     vis[dx][dy][t.state] = ;
                     s.x = dx;
                     s.y = dy;
                     s.step=t.step+;
                     s.state = t.state;
                     q.push(s);

                 }
                 else if (a[dx][dy]>='A' && a[dx][dy]<='J')
                 {
                     if ((<<(a[dx][dy]-'A'))&t.state)//判断是否拿到过能打开当前门的钥匙
                     {
                         vis[dx][dy][t.state] = ;
                         s.x = dx;
                         s.y = dy;
                         s.step = t.step+;
                         s.state = t.state;
                         q.push(s);
                     }
                 }
                 else if (a[dx][dy]>='a' && a[dx][dy] <= 'j')
                 {
                     int state= ((<<(a[dx][dy]-'a'))|t.state);//更新此时拿到的钥匙的状态
                     if (!vis[dx][dy][state])
                     {
                         vis[dx][dy][state] = ;
                         s.x = dx;
                         s.y = dy;
                         s.step = t.step+;
                         s.state = state;
                         q.push(s);
                     }

                 }
             }
         }
     }
 }
 int main()
 {
     int t;
     while(~scanf("%d%d%d%*c",&n,&m,&t))
     {
         Time = -;
         for (int i = ; i < n; i++)
             scanf("%s",a[i]);
         for (int i = ; i < n; i++)
         {
             for (int j = ; j < m; j++)
             {
                 if (a[i][j]=='@')
                 {
                     s_x = i;
                     s_y = j;
                 }
                 if (a[i][j]=='^')
                 {
                     e_x = i;
                     e_y = j;
                 }
             }
         }
         bfs();
         if (Time < t && Time!=-)
             printf("%d\n",Time);
         else
             printf("-1\n");
     }
     return ;
 }