ZOJ(1649)Rescue

#include <iostream>
#include <stdio.h>
#include <string>
#include <string.h>
#include <algorithm>
#include <stdlib.h>
#include <math.h>
#include <queue>
using namespace std;
const int maxn = 205;
const int inf = 0xfffffff;
struct node{
    int x,y;
    int step;
    int time;
    void set(int xx,int yy,int s,int t){
        x = xx; y = yy; step = s; time = t;
    }
};

int n,m;
int sx,sy,ax,ay;
int dir[4][2] = {1,0,0,1,-1,0,0,-1};
char grid[maxn][maxn];
int mintime[maxn][maxn];

int cango(int x,int y){
    return (x>=1&&x<=n&&y>=1&&y<=m);
}
void init(){
    for(int i = 1;i <= n;i++)
        for(int j = 1;j <= m;j++)
            mintime[i][j] = inf;
}

void bfs(node start){
    node now,next;
    queue<node>que;
    que.push(start);
    while(!que.empty()){
        now = que.front();
        que.pop();
        for(int i = 0;i < 4;i++){
            int xx = now.x + dir[i][0];
            int yy = now.y + dir[i][1];
            if(cango(xx, yy)&&grid[xx][yy] != '#'){
                next.set(xx,yy,now.step+1,now.time+1);
                if(grid[xx][yy] == 'x')
                    next.time++;
                if(next.time<mintime[xx][yy]){
                    mintime[xx][yy] = next.time;
                    que.push(next);
                }
            }
        }
    }
}

int main(){
    while(~scanf("%d%d",&n,&m)){
        for(int i = 1;i <= n;i++)
            scanf("%s",grid[i]+1);
        for(int i = 1;i <= n;i++)
            for(int j = 1;j <= m;j++){
                if(grid[i][j] == 'a'){
                    ax = i;
                    ay = j;
                }
                if(grid[i][j] == 'r'){
                    sx = i;
                    sy = j;
                }
            }
        node st;
        init();
        st.set(sx,sy,0,0);
        bfs(st);
        /*for(int i = 1;i <= n;i++){
            for(int j = 1;j <= m;j++)
                printf("%10d ",mintime[i][j]);
            printf("\n");
        }*/
        if(mintime[ax][ay] != inf)
            printf("%d\n",mintime[ax][ay]);
        else
            printf("Poor ANGEL has to stay in the prison all his life.\n");
    }
    return 0;
}