【HDOJ】2612 Find a way

BFS。

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

 #define INF 0x3fffffff

 typedef struct node_st {
     int x, y, s;
     node_st() {}
     node_st(int xx, int yy, int ss) {
         x = xx; y = yy; s = ss;
     }
 } node_st;

 char visit[][];
 char map[][];
 int step[][][];
 int n, m;
 int direct[][] = {{-,},{,},{,-},{,}};

 void bfs(int x, int y, int sel) {
     int i, s;
     queue<node_st> que;
     node_st node;

     memset(visit, , sizeof(visit));
     memset(step[sel], , sizeof(step[sel]));
     visit[x][y] = ;
     que.push(node_st(x,y,));

     while ( !que.empty() ) {
         node = que.front();
         que.pop();
         s = node.s + ;
         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])
                 continue;
             visit[x][y] = ;
             if (map[x][y] == '#')
                 continue;
             if (map[x][y] == '@')
                 step[sel][x][y] = s;
             que.push(node_st(x,y,s));
         }
     }
 }

 int main() {
     int i, j, tmp, min;
     int yx, yy, mx, my;

     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] == 'Y') {
                     yx = i;
                     yy = j;
                 } else if (map[i][j] == 'M') {
                     mx = i;
                     my = j;
                 }
             }
         }
         bfs(yx, yy, );
         bfs(mx, my, );
         min = INF;
         for (i=; i<n; ++i) {
             for (j=; j<m; ++j) {
                 if (step[][i][j] && step[][i][j]) {
                     tmp = step[][i][j] + step[][i][j];
                     if (tmp < min)
                         min = tmp;
                 }
             }
         }
         printf("%d\n", min*);
     }

     return ;
 }