【HDOJ】1180 诡异的楼梯

bfs+优先队列。wa了N次，才发现可以停留等待楼梯变换方向。

 #include <iostream>
 #include <queue>
 #include <cstdio>
 #include <cstring>
 using namespace std;

 #define MAXNUM 55

 typedef struct node_st {
     int x, y, t;
     node_st() {}
     node_st(int xx, int yy, int tt) {
         x = xx; y = yy; t = tt;
     }
     friend bool operator < (node_st a, node_st b) {
         return a.t > b.t;
     }
 } node_st;

 char map[MAXNUM][MAXNUM];
 char visit[MAXNUM][MAXNUM];
 int n, m;
 int begx, begy, endx, endy;
 int direct[][] = {{,},{-,},{,},{,-}};

 int bfs(int begx, int begy) {
     priority_queue<node_st> que;
     node_st node;
     int i, x, y, nx, ny, t;

     que.push(node_st(begx, begy, ));
     memset(visit, , sizeof(visit));
     visit[begx][begy] = ;

     while ( !que.empty() ) {
         node = que.top();
         if (map[node.x][node.y] == 'T') {
             return node.t;
         }
         que.pop();
         for (i=; i<; ++i) {
             x = node.x + direct[i][];
             y = node.y + direct[i][];
             if (x< || x>=n || y< || y>=m)
                 continue;
             if (visit[x][y] || map[x][y] == '*')
                 continue;
             if (map[x][y] == '.' || map[x][y]=='T') {
                 que.push(node_st(x,y,node.t+));
                 visit[x][y] = ;
                 continue;
             }
             if (map[x][y]=='|' || map[x][y]=='-') {
                 nx = x + direct[i][];
                 ny = y + direct[i][];
                 t = node.t + ;
                 if (nx< || nx>=n || ny< || ny>=m)
                     continue;
                 if (visit[nx][ny] || map[nx][ny]=='*')
                     continue;
                 if ( ((map[x][y]=='|') && ((node.t&)==) && (i==||i==)) ||
                      ((map[x][y]=='|') && ((node.t&)!=) && (i==||i==)) ||
                      ((map[x][y]=='-') && ((node.t&)==) && (i==||i==)) ||
                      ((map[x][y]=='-') && ((node.t&)!=) && (i==||i==)) )
                      ++t;
                 visit[nx][ny] = ;
                 que.push(node_st(nx, ny, t));
             }
         }
     }

     return -;
 }

 int main() {
     int i, j;

     while (scanf("%d %d%*c",&n,&m) != EOF) {
         for (i=; i<n; ++i) {
             scanf("%s", map[i]);
             for (j=; j<m; ++j) {
                 if (map[i][j] == 'S') {
                     begx = i;
                     begy = j;
                 }
             }
         }
         i = bfs(begx, begy);
         printf("%d\n", i);
     }

     return ;
 }