PKU 2251 用DFS TLE了 BFS AC了

Dungeon Master

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 6561		Accepted: 2610

Description

You are trapped in a 3D dungeon and need to find the quickest way out! The dungeon is composed of unit cubes which may or may not be filled with rock. It takes one minute to move one unit north, south, east, west, up or down. You cannot move diagonally and the maze is surrounded by solid rock on all sides.

Is an escape possible? If yes, how long will it take?

Input

The input consists of a number of dungeons. Each dungeon description starts with a line containing three integers L, R and C (all limited to 30 in size).
L is the number of levels making up the dungeon.
R and C are the number of rows and columns making up the plan of each level.
Then there will follow L blocks of R lines each containing C characters. Each character describes one cell of the dungeon. A cell full of rock is indicated by a '#' and empty cells are represented by a '.'. Your starting position is indicated by 'S' and the exit by the letter 'E'. There's a single blank line after each level. Input is terminated by three zeroes for L, R and C.

Output

Each maze generates one line of output. If it is possible to reach the exit, print a line of the form

Escaped in x minute(s).

where x is replaced by the shortest time it takes to escape.
If it is not possible to escape, print the line

Trapped!

Sample Input

3 4 5
S....
.###.
.##..
###.#
#####
#####
##.##
##...
#####
#####
#.###
####E
1 3 3
S##
#E#
###
0 0 0

Sample Output

Escaped in 11 minute(s).
Trapped!

三维迷宫问题
据说要用BFS，范围30 ，我以为DFS能搞定的，为什么会超时呢？？？？

#include<iostream>
2

#include<string.h>
3

using namespace std;
4

char G[35][35][35];
5

bool g[35][35][35];
6

void dfs(int l,int r,int c)
7

{
8

if(G[l][r][c]==0||G[l][r][c]=='#')return ;
9

if((G[l+1][r][c]=='.'||G[l+1][r][c]>G[l][r][c])&&G[l+1][r][c]!=0&&G[l+1][r][c]!='#')

{ G[l+1][r][c]=G[l][r][c]+1;g[l+1][r][c]=1;dfs(l+1,r,c);}
10

if((G[l][r-1][c]=='.'||G[l][r-1][c]>G[l][r][c])&&G[l][r-1][c]!=0&&G[l][r-1][c]!='#')

{ G[l][r-1][c]=G[l][r][c]+1;g[l][r-1][c]=1;dfs(l,r-1,c);}
11

if((G[l][r+1][c]=='.'||G[l][r+1][c]>G[l][r][c])&&G[l][r+1][c]!=0&&G[l][r+1][c]!='#')

{ G[l][r+1][c]=G[l][r][c]+1;g[l][r+1][c]=1;dfs(l,r+1,c);}
12

if((G[l][r][c-1]=='.'||G[l][r][c-1]>G[l][r][c])&&G[l][r][c-1]!=0&&G[l][r][c-1]!='#')

{ G[l][r][c-1]=G[l][r][c]+1;g[l][r][c-1]=1;dfs(l,r,c-1);}
13

if((G[l][r][c+1]=='.'||G[l][r][c+1]>G[l][r][c])&&G[l][r][c+1]!=0&&G[l][r][c+1]!='#')

{ G[l][r][c+1]=G[l][r][c]+1;g[l][r][c+1]=1;dfs(l,r,c+1);}
14

if((G[l-1][r][c]=='.'||G[l-1][r][c]>G[l][r][c])&&G[l-1][r][c]!=0&&G[l-1][r][c]!='#')

{ G[l-1][r][c]=G[l][r][c]+1;g[l-1][r][c]=1;dfs(l-1,r,c);}
15

}
16

int main()
18

{
19

int i,j,k,l,r,c,sl,sr,sc,el,er,ec; //起点，终点
20

while(cin>>l>>r>>c,l||r||c)
21

{
22

memset(G,0,sizeof (G));
23

memset(g,0,sizeof (g));
24

for(i=1; i<=l ;i++)
25

for(j=1; j<=r; j++)
26

for(k=1; k<=c; k++)
27

{
28

cin>>G[i][j][k];
29

if(G[i][j][k]=='S')
30

{ sl=i; sr=j; sc=j; G[i][j][k]=1; g[i][j][k]=1; }
31

else if(G[i][j][k]=='E')
32

{el=i; er=j; ec=k; G[i][j][k]=127; }
33

}
34

dfs(sl,sr,sc);
36

/**//* for(i=1; i<=l ; i++,cout<<endl)
37

for(j=1; j<=r; j++,cout<<endl)
38

for(k=1; k<=c; k++)
39

cout<<(int)G[i][j][k]<<" ";
40

for(i=1; i<=l ; i++,cout<<endl)
41

for(j=1; j<=r; j++,cout<<endl)
42

for(k=1; k<=c; k++)
43

cout<<(int)g[i][j][k]<<" ";
44

*/if(g[el][er][ec]==0)cout<<"Trapped!"<<endl;
45

else cout<<"Escaped in "<<int(G[el][er][ec]-1)<<" minute(s)."<<endl;
46

}
47

// system("pause");
48

return 0;
49

}

写个BFS终于过了，只要在平面的迷宫基础上在垂直方向往上，往下都搜两次就可以了

1 #include < iostream >
2 #include < string .h >
3 #include < queue >
4 using namespace std;
5 char G[ 35 ][ 35 ][ 35 ];
6 int cnt[ 35 ][ 35 ][ 35 ];
7 struct type
8 { int l,r,c; };
9
10 int main()
11 {
12      int l,c,r,sl,sc,sr,el,ec,er,i,j,k;
13      void bfs( int sl, int sr, int sc);
14      while (cin >> l >> r >> c,l || c || r)
15     {
16       memset(G, 0 , sizeof (G));
17       memset(cnt, 0 , sizeof (cnt));
18        for (i = 1 ; i <= l; i ++ )
19        for (j = 1 ; j <= r; j ++ )
20        for (k = 1 ; k <= c; k ++ )
21       {
22         cin >> G[i][j][k];
23          if (G[i][j][k] == ' S ' ){sl = i; sr = j; sc = k; }
24          else if (G[i][j][k] == ' E ' ){el = i; er = j; ec = k; }
25       }
26
27       bfs(sl,sr,sc);
28     //   for(i=1; i<=l; i++,cout<<endl)
29      // for(j=1; j<=r; j++,cout<<endl)
30       // for(k=1; k<=c; k++)
31       // cout<<cnt[i][j][k]<<' ';
32
33      if (el == sl && er == sr && ec == sc)cout << " Escaped in " << 0 << " minute(s). " << endl;
34      else if (cnt[el][er][ec] > 0 )cout << " Escaped in " << cnt[el][er][ec] << " minute(s). " << endl;
35      else cout << " Trapped! " << endl;
36     }
37     // system("pause");
38      return 0 ;
39 }
40
41 bool valid( int l, int r, int c)
42 {
43    return (G[l][r][c] == ' . ' || G[l][r][c] == ' E ' );
44 }
45
46 void bfs( int sl, int sr, int sc)
47 {
48   queue < struct type > q;
49    struct type tem; tem.l = sl; tem.r = sr; tem.c = sc;
50   q.push(tem);
51    while (q.size())
52   {
53     tem = q.front(); q.pop();
54      int l = tem.l,r = tem.r,c = tem.c;
55      if (valid(l,r + 1 ,c) && cnt[l][r + 1 ][c] == 0 ){cnt[l][r + 1 ][c] = cnt[l][r][c] + 1 ;tem.l = l; tem.r = r + 1 ; tem.c = c; q.push(tem); }
56      if (valid(l,r - 1 ,c) && cnt[l][r - 1 ][c] == 0 ){cnt[l][r - 1 ][c] = cnt[l][r][c] + 1 ;tem.l = l; tem.r = r - 1 ; tem.c = c; q.push(tem); }
57      if (valid(l,r,c + 1 ) && cnt[l][r][c + 1 ] == 0 ){cnt[l][r][c + 1 ] = cnt[l][r][c] + 1 ;tem.l = l; tem.r = r; tem.c = c + 1 ; q.push(tem); }
58      if (valid(l,r,c - 1 ) && cnt[l][r][c - 1 ] == 0 ){cnt[l][r][c - 1 ] = cnt[l][r][c] + 1 ;tem.l = l; tem.r = r; tem.c = c - 1 ; q.push(tem); }
59      if (valid(l - 1 ,r,c) && cnt[l - 1 ][r][c] == 0 ){cnt[l - 1 ][r][c] = cnt[l][r][c] + 1 ;tem.l = l - 1 ; tem.r = r; tem.c = c; q.push(tem); }
60      if (valid(l + 1 ,r,c) && cnt[l + 1 ][r][c] == 0 ){cnt[l + 1 ][r][c] = cnt[l][r][c] + 1 ;tem.l = l + 1 ; tem.r = r; tem.c = c; q.push(tem); }
61
62   }
63 }

PKU 2251 用DFS TLE了 BFS AC了

PKU 2251 用DFS TLE了 BFS AC了

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