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
Is an escape possible? If yes, how long will it take?
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
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.
Each maze generates one line of output. If it is possible to reach the exit, print a line of the form
where x is replaced by the shortest time it takes to escape.
If it is not possible to escape, print the line
Sample Input
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!
3 4 5 S.... .###. .##.. ###.# ##### ##### ##.## ##... ##### ##### #.### ####E 1 3 3 S## #E# ### 0 0 0Sample Output
Escaped in 11 minute(s). Trapped!
这个网址有BFS例子具体的实现过程：
走迷宫具体的实现过程 很详细
//走迷宫问题用bfs来做，会判断这一个点是否可走，找到最优路径
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#include<iostream>
#include<algorithm>
using namespace std;
struct node
{
int L,R,C;
int step;
}t[1000001];
struct node p,q,w,l;
char mp3[31][31][31];
int dir3[][3]={0,0,1,0,0,-1,0,-1,0,0,1,0,-1,0,0,1,0,0};
int vis[31][31][31];
int L,R,C;
void bfs() // 用队列来实现
{
vis[p.L][p.R][p.C]=1;
int front=0;
int rear=0;
t[rear++]=p;
while(front!=rear)
{
w=t[front++];
if(w.L==q.L && w.R==q.R && w.C==q.C)//判断是否到达终点
{
printf("Escaped in %d minute(s).\n",w.step);
return ;
}
for(int i=0;i<6;i++)
{
l=w;
l.L=l.L+dir3[i][0];
l.R=l.R+dir3[i][1];
l.C=l.C+dir3[i][2];
if(l.L>=0&&l.L<L&&l.R>=0&&l.R<R&&l.C>=0&&l.C<C&&mp3[l.L][l.R][l.C]!='#'&&vis[l.L][l.R][l.C]==0)
{
l.step++;
vis[l.L][l.R][l.C]=1;
t[rear++]=l;
}
}
}
printf("Trapped!\n");
}
int main()
{
while(scanf("%d%d%d",&L,&R,&C)!=EOF)
{
getchar();
memset(mp3,0,sizeof(mp3));
memset(vis,0,sizeof(vis));
memset(t,0,sizeof(t)) ;
if(L==0 || R==0 || C==0)
{
break;
}
for(int i=0;i<L;i++) //三维字符串的输入方式
{
for(int j=0;j<R;j++)
{
scanf("%s",mp3[i][j]);
for(int k=0;k<C;k++)
{
if(mp3[i][j][k]=='S') //起点
{
p.L=i;
p.R=j;
p.C=k;
p.step=0;
}
else if(mp3[i][j][k]=='E') //终点
{
q.L=i;
q.R=j;
q.C=k;
}
}
}
}
bfs();
}
return 0;
}