1 #include<iostream>
 2 #include<stdio.h>
 3 #include<cstring>
 4 using namespace std;
 5 # define ll long long
 6 const int maxn =2100;
 7 char str[maxn][maxn];
 8 int vis[maxn];
 9 int n,m,num;
10 void dfs(int u,int cnt)
11 {
12     if(cnt==m)
13     {
14         num++;
15         return ;
16     }
17     if(u==n)
18         return ;
19     for(int i=0; i<n; i++)
20     {
21         if(!vis[i]&&str[u][i]=='#')
22         {
23             vis[i]=1;
24             dfs(u+1,cnt+1);
25             vis[i]=0;
26         }
27     }
28     dfs(u+1,cnt);
29 }
30 int main()
31 {
32     while(~scanf("%d %d",&n,&m))
33     {
34         if(n==-1&&m==-1)
35             break;
36         memset(vis,0,sizeof(vis));
37         num=0;
38         for(int i=0; i<n; i++)
39         {
40             scanf("%s",str[i]);
41         }
42         dfs(0,0);
43         printf("%d\n",num);
44     }
45     return 0;
46 }

 1 #include<iostream>
 2 #include<stdio.h>
 3 #include<cstring>
 4 #include<queue>
 5 using namespace std;
 6 # define ll long long
 7 const int maxn =50;
 8 char str[maxn][maxn][maxn];
 9 int vis[maxn][maxn][maxn];
10 int f[3][6]= {{1,-1,0,0,0,0},
11     {0,0,-1,1,0,0},
12     {0,0,0,0,1,-1}
13 };
14 int n,m,k;
15 int stx,sty,stz;
16 int edx,edy,edz;
17 int ans;
18 bool judge(int x,int y,int z)
19 {
20     if(x>=1&&x<=n&&y>=1&&y<=m&&z>=1&&z<=k)
21         return true;
22     return false;
23 }
24 struct node
25 {
26     int x,y,z,step;
27     node() {}
28     node(int xx,int yy,int zz,int tt)
29     {
30         x=xx,y=yy,z=zz,step=tt;
31     }
32 };
33 void bfs(int x,int y,int z)
34 {
35     queue<node>q;
36     q.push(node(x,y,z,0));
37     vis[x][y][z]=1;
38     while(!q.empty())
39     {
40         node top=q.front();
41         q.pop();
42         if(top.x==edx&&top.y==edy&&top.z==edz)
43         {
44             ans=top.step;
45             return ;
46         }
47         for(int i=0; i<6; i++)
48         {
49             int tx,ty,tz;
50             tx=top.x+f[0][i];
51             ty=top.y+f[1][i];
52             tz=top.z+f[2][i];
53             if(judge(tx,ty,tz)&&vis[tx][ty][tz]==0&&str[tx][ty][tz]!='#')
54             {
55                 vis[tx][ty][tz]=1;
56                 q.push(node(tx,ty,tz,top.step+1));
57             }
58         }
59     }
60 }
61     int main()
62     {
63         while(~scanf("%d %d %d",&n,&m,&k)&&(n+m+k))
64         {
65             memset(vis,0,sizeof(vis));
66             ans=-1;
67             for(int i=1; i<=n; i++)
68             {
69                 for(int j=1; j<=m; j++)
70                 {
71                     scanf("%s",str[i][j]+1);
72                     for(int l=1; l<=k; l++)
73                     {
74                         if(str[i][j][l]=='S')
75                         {
76                             stx=i;
77                             sty=j;
78                             stz=l;
79                         }
80                         if(str[i][j][l]=='E')
81                         {
82                             edx=i;
83                             edy=j;
84                             edz=l;
85                         }
86                     }
87                 }
88             }
89             bfs(stx,sty,stz);
90             if(ans==-1)
91                 printf("Trapped!\n");
92             else
93                 printf("Escaped in %d minute(s).\n",ans);
94         }
95         return 0;
96     }

 1 #include<iostream>
 2 #include<stdio.h>
 3 #include<cstring>
 4 #include<queue>
 5 using namespace std;
 6 # define ll long long
 7 const int maxn =2e5+100;
 8 int vis[maxn];
 9 pair<int,int> top;
10 int  bfs(int st,int ed){
11 queue<pair<int,int> >q;
12 vis[st]=1;
13 q.push(make_pair(st,0));
14 while(!q.empty()){
15 top=q.front();
16 q.pop();
17 if(top.first==ed){
18 return top.second;
19 }
20 if(top.first+1<=ed&&vis[top.first+1]==0){
21 vis[top.first+1]=1;
22 q.push(make_pair(top.first+1,top.second+1));
23 }
24 if(top.first-1>=0&&vis[top.first-1]==0){
25 vis[top.first-1]=1;
26 q.push(make_pair(top.first-1,top.second+1));
27 }
28 if(top.first*2<=2*ed&&vis[top.first*2]==0){
29 vis[top.first*2]=1;
30 q.push(make_pair(top.first*2,top.second+1));
31 }
32 }
33 }
34 int main(){
35 int n,m;
36 while(~scanf("%d %d",&n,&m)){
37 memset(vis,0,sizeof(vis));
38 int ans=bfs(n,m);
39 printf("%d\n",ans);
40 }
41 return 0;
42 }