题目链接：http://poj.org/problem?id=2251
注意：细心细心再细心！！
1 #include<iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<queue> 5 using namespace std; 6 7 const int maxn = 35; 8 int L,R,C; 9 bool vis[maxn][maxn][maxn]; 10 char maze[maxn][maxn][maxn]; 11 int go[6][3] = {0,0,1,0,0,-1,0,1,0,0,-1,0,1,0,0,-1,0,0}; 12 struct node 13 { 14 int x,y,z; 15 int count; 16 }now,nex; 17 18 bool IsOk(node s) 19 { 20 return (s.x>=0&&s.x<L&&s.y>=0&&s.y<R&&s.z>=0&&s.z<C&&!vis[s.x][s.y][s.z]&&maze[s.x][s.y][s.z]!='#'); 21 } 22 23 int bfs() 24 { 25 queue<node> Q; 26 vis[now.x][now.y][now.z]=1; 27 Q.push(now); 28 while(!Q.empty()) 29 { 30 now = Q.front(); 31 Q.pop(); 32 if(maze[now.x][now.y][now.z]=='E') 33 return now.count; 34 for(int i=0;i<6;i++) 35 { 36 nex.x = now.x + go[i][0]; 37 nex.y = now.y + go[i][1]; 38 nex.z = now.z + go[i][2]; 39 if(IsOk(nex)) 40 { 41 vis[nex.x][nex.y][nex.z]=1; 42 nex.count = now.count + 1; 43 Q.push(nex); 44 } 45 } 46 } 47 return 0; 48 } 49 50 int main() 51 { 52 while(~scanf("%d%d%d",&L,&R,&C)&&(L||R||C)) 53 { 54 for(int i=0;i<L;i++) 55 { 56 for(int j=0;j<R;j++) 57 scanf("%s",maze[i][j]); 58 getchar(); 59 } 60 int flag = 0; 61 for(int i=0;i<L;i++) 62 { 63 for(int j=0;j<R;j++) 64 { 65 for(int k=0;k<C;k++) 66 if(maze[i][j][k]=='S') 67 { 68 now.x=i;now.y=j;now.z=k; 69 now.count=0; 70 flag = 1; 71 break; 72 } 73 if(flag) 74 break; 75 } 76 if(flag) 77 break; 78 } 79 memset(vis,0,sizeof(vis)); 80 int ans = bfs(); 81 if(ans) 82 printf("Escaped in %d minute(s). ",ans); 83 else 84 printf("Trapped! "); 85 } 86 return 0; 87 }
复习一遍，代码和上面的稍有不同：
1 #include<cstdio> 2 #include<cstring> 3 #include<queue> 4 using namespace std; 5 6 const int maxn = 30; 7 char maze[maxn][maxn][maxn]; 8 bool vis[maxn][maxn][maxn]; 9 int go[6][3] = {0,0,1,0,0,-1,1,0,0,-1,0,0,0,-1,0,0,1,0}; 10 int l,r,c; 11 int sx,sy,sz; 12 struct Point 13 { 14 int x,y,z; 15 int cnt; 16 }now,nex; 17 18 bool IsOk(Point s) 19 { 20 if(s.x<0||s.x>=l||s.y<0||s.y>=r||s.z<0||s.z>=c) 21 return 0; 22 else if(maze[s.x][s.y][s.z] == '#') 23 return 0; 24 else if(vis[s.x][s.y][s.z]) 25 return 0; 26 else 27 return 1; 28 } 29 int BFS() 30 { 31 now.x = sx;now.y = sy;now.z = sz; 32 now.cnt = 0; 33 vis[sx][sy][sz] = 1; 34 queue<Point> q; 35 q.push(now); 36 while(!q.empty()) 37 { 38 now = q.front(); 39 q.pop(); 40 if(maze[now.x][now.y][now.z] == 'E') 41 { 42 return now.cnt; 43 } 44 for(int i=0;i<6;i++) 45 { 46 nex.x = now.x + go[i][0]; 47 nex.y = now.y + go[i][1]; 48 nex.z = now.z + go[i][2]; 49 if(IsOk(nex)) 50 { 51 vis[nex.x][nex.y][nex.z] = 1; 52 nex.cnt = now.cnt + 1; 53 q.push(nex); 54 } 55 } 56 } 57 return -1; 58 } 59 60 int main() 61 { 62 while(~scanf("%d%d%d",&l,&r,&c)&&(l||r||c)) 63 { 64 for(int i=0;i<l;i++) 65 { 66 for(int j=0;j<r;j++) 67 scanf("%s",maze[i][j]); 68 getchar(); 69 } 70 bool flag = 0; 71 for(int i=0;i<l;i++) 72 { 73 for(int j=0;j<r;j++) 74 { 75 for(int k=0;k<c;k++) 76 { 77 if(maze[i][j][k] == 'S') 78 { 79 sx = i;sy = j;sz = k; 80 flag = 1; 81 break; 82 } 83 } 84 if(flag) 85 break; 86 } 87 if(flag) 88 break; 89 } 90 memset(vis,0,sizeof(vis)); 91 int ans = BFS(); 92 if(ans==-1) 93 printf("Trapped! "); 94 else 95 printf("Escaped in %d minute(s). ",ans); 96 } 97 return 0; 98 }