立体最短路径，广搜(POJ2251)

#include <stdio.h>
#include <algorithm>
#include <string.h>
#include <queue>

using namespace std;

char map[35][35][35];///存放地图
bool hash[35][35][35];///这条路是否走过

struct point{
int x;  ///l
int y;  ///r
int z;  ///c
int step;///移动的步数
};

int main()
{
int l,r,c;
while(scanf("%d%d%d",&l,&r,&c),l&&r&&c)
{
int i,j,k;
point start;

memset(hash,false,sizeof(hash));

for(i=0;i<l;i++)
{
for(j=0;j<r;j++)
{
scanf("%s",map[i][j]);
for(k=0;k<c;k++)
{
if(map[i][j][k]=='S')
{
///对起点初始化
start.x=i;
start.y=j;
start.z=k;
start.step=0;

hash[i][j][k]=true;///这条路走过了
}
}
}
}

queue<point> bfs;

bfs.push(start);///入队

bool found=false;    ///是否找到最优解

while(!bfs.empty())
{
point tmp=bfs.front();

bfs.pop();

if(map[tmp.x][tmp.y][tmp.z]=='E')
{
found=true;
printf("Escaped in %d minute(s).\n",tmp.step);
break;
}

tmp.step++;

point tmp2;

if(tmp.x>0) ///向下走
{
tmp2=tmp;
tmp2.x--;
if(map[tmp2.x][tmp2.y][tmp2.z]!='#'&&hash[tmp2.x][tmp2.y][tmp2.z]==false)
{
///如果下一层不是障碍物并且没走过，则往下走，标记该点，入队
hash[tmp2.x][tmp2.y][tmp2.z]=true;
bfs.push(tmp2);
}
}

///向上走
if(tmp.x<l-1)
{
tmp2=tmp;
tmp2.x++;
if(map[tmp2.x][tmp2.y][tmp2.z]!='#'&&hash[tmp2.x][tmp2.y][tmp2.z]==false)
{
hash[tmp2.x][tmp2.y][tmp2.z]=true;
bfs.push(tmp2);
}
}

///向北走
if(tmp.y>0)
{
tmp2=tmp;
tmp2.y--;
if(map[tmp2.x][tmp2.y][tmp2.z]!='#'&&hash[tmp2.x][tmp2.y][tmp2.z]==false)
{
hash[tmp2.x][tmp2.y][tmp2.z]=true;
bfs.push(tmp2);
}
}

///向南走
if(tmp.y<r-1)
{
tmp2=tmp;
tmp2.y++;
if(map[tmp2.x][tmp2.y][tmp2.z]!='#'&&hash[tmp2.x][tmp2.y][tmp2.z]==false)
{
hash[tmp2.x][tmp2.y][tmp2.z]=true;
bfs.push(tmp2);
}
}

///向西走
if(tmp.z>0)
{
tmp2=tmp;
tmp2.z--;
if(map[tmp2.x][tmp2.y][tmp2.z]!='#'&&hash[tmp2.x][tmp2.y][tmp2.z]==false)
{
hash[tmp2.x][tmp2.y][tmp2.z]=true;
bfs.push(tmp2);
}
}

///向东走
if(tmp.z<c-1)
{
tmp2=tmp;
tmp2.z++;
if(map[tmp2.x][tmp2.y][tmp2.z]!='#'&&hash[tmp2.x][tmp2.y][tmp2.z]==false)
{
hash[tmp2.x][tmp2.y][tmp2.z]=true;
bfs.push(tmp2);
}
}

}
if(!found)
printf("Trapped!\n");

}
return 0;
}