第一次用容器做的BFS题目，题目有个地方比较坑，就是遍历时的方向，比如上下左右能AC，右上左下就WA

#include <stdio.h>

#include <string.h>

#include <iostream>

#include <queue>

using namespace std;

char map[205][205];

int x_begin,y_begin,flag,n,m;

int v[205][205],d[4][2] = { {-1,0},{1,0},{0,-1},{0,1} };

struct node

{

    int x;

    int y;

    int step;

};

void bfs()

{

    queue <node> q;

    node s,temp;

    s.x = x_begin;

    s.y = y_begin;

    s.step = 0;

    v[x_begin][y_begin] = 0;

    q.push(s);

    while(!q.empty())

    {

        temp = q.front();

        q.pop();

        if(map[temp.x][temp.y] == 'r')

        {

            printf("%d\n",temp.step);

            flag = 1;

            return ;

        }

        for(int i = 0 ; i < 4 ; i ++)

        {

            s = temp;//temp为本次遍历的结点

            s.x += d[i][0];

            s.y += d[i][1];

            if(s.x >= 0 && s.x < n && s.y >= 0 && s.y < m && map[s.x][s.y] != '#')

            {

                if(map[s.x][s.y] == 'x')//杀一个守卫时间+2

                    s.step += 2;

                else

                    s.step ++;

                if(v[s.x][s.y] >= s.step)

                {

                    v[s.x][s.y] = s.step;

                    q.push(s);

                }

            }

        }

    }

}

int main()

{

    int i,j;

    while(~scanf("%d%d",&n,&m))

    {

        for(i = 0 ; i < n ; i ++)

        {

            scanf("%s",map[i]);

            for(j = 0 ; j < m ; j ++)

            if(map[i][j] == 'a')

            {

                x_begin = i;

                y_begin = j;

            }

        }

        memset(v,1,sizeof(v));

        flag = 0;

        bfs();

        if(!flag)

          printf("Poor ANGEL has to stay in the * all his life.\n");

    }

    return 0;

}