HDU 1242

http://acm.hdu.edu.cn/showproblem.php?pid=1242

#include<stdio.h>  
#include<string.h>  
#include<iostream>  
#include<queue>  
using namespace std;  
int dir[4][2]={0,1,0,-1,1,0,-1,0};  
int si,sj;//公主的起始横纵坐标，
int n,m;  
char map[201][201];  
struct node  
{  
    int x,y;  
    int time;  
};  
priority_queue<node> q;  
bool operator<(node a,node b)  
{  
    return a.time>b.time;  
}  
int out_line(int a,int b)  
{  
    if(a >= 0 && a< n && b>=0 && b < n)return 1;  
    else return 0;  
}  
void getmap()  
{  
    int i,j;  
    memset(map,0,sizeof(map));  
    for(i=0;i<n;i++)  
        for(j=0;j<m;j++)  
        {  
            scanf("%1s",&map[i][j]);  
            if(map[i][j]=='a') si=i,sj=j;  
        }  
}  
int bfs(int si,int sj)  
{  
    int i,mark[201][201];  
    node cur,next;  
    while(!q.empty())  //清队列
        q.pop();  
    memset(mark,0,sizeof(mark));  
    cur.x=si, cur.y=sj, cur.time=0, mark[cur.x][cur.y]=1;  
    q.push(cur);  
    while(!q.empty())  
    {  
        cur=q.top();  
        q.pop();  
        for(i=0;i<4;i++)  
        {  
            next.x=cur.x+dir[i][0];  
            next.y=cur.y+dir[i][1];  
            if(!mark[next.x][next.y] && out_line(next.x,next.y) &&  
                map[next.x][next.y]!='#')  
            {  
                mark[next.x][next.y]=1;  
                if(map[next.x][next.y]=='x')next.time=cur.time+2;  
                else next.time=cur.time+1;  
                if(map[next.x][next.y]=='r') return next.time;  
                q.push(next);  
            }  
        }  
    }  
    return -1;  
}  
int main()  
{  
    int ans;  
    while(~scanf("%d%d",&n,&m))  
    {  
        getmap();  
        ans=bfs(si,sj);  
        if(ans==-1)  
            printf("Poor ANGEL has to stay in the prison all his life.\n");  
        else printf("%d\n",ans);  
    }  
    return 0;  
}