zoj 1649 BFS

// zoj 1649
#include<stdio.h>
#include<queue>
#include<string.h>
using namespace std;
#define MAXN 200
#define INF 1000000
struct point
{
int x,y;
int step,time;
};
queue<point> Q;
int N,M,ax,ay;
char map[MAXN][MAXN];
int time[MAXN][MAXN];
int dir[4][2]={{-1,0},{1,0},{0,-1},{0,1}};
int bfs(point s)
{
int i;
Q.push(s);
point jk;
while(!Q.empty())
{
jk=Q.front();
Q.pop();
for(i=0; i<4;i++)
{
int x=jk.x+dir[i][0];
int y=jk.y+dir[i][1];
if(x>=0&&x<=N-1&&y>=0&&y<=M-1&&map[x][y]!='#')
{
point t;
t.x=x;
t.y=y;
t.step=jk.step+1;
t.time=jk.time+1;
if(map[x][y]=='x')
t.time++;
if(t.time<time[x][y])
{
time[x][y]=t.time;
Q.push(t);
}
}
}
}
return time[ax][ay];
}
int main()
{
int i,j;
//freopen("input.txt","r",stdin);
while(scanf("%d%d",&N,&M)!=EOF)
{
memset(map,0,sizeof(map));
for(i=0; i<N; i++)
scanf("%s",map[i]);
int sx,sy;
point start;
for(i=0; i<N; i++)
for(j=0; j<M; j++)
{
time[i][j]=INF;
if(map[i][j]=='a')
{
ax=i;
ay=j;
}
else if(map[i][j]=='r')
{
sx=i;
sy=j;
}
}
start.x=sx;
start.y=sy;
start.step=0;
start.time=0;
int min=bfs(start);
if(min<INF)
printf("%d\n",min);
else printf("Poor ANGEL has to stay in the prison all his life.\n");
}
return 0;
}