题目链接
Rescue
代码如下

#include<bits/stdc++.h>
using namespace std;
const int M = 205;
int dx[] = {1,0,0,-1};
int dy[] = {0,1,-1,0};
int n,m;
int vis[M][M];char mp[M][M];
struct dot
{
	int x,y,time;
};
bool in(dot gx)
{
	if(gx.x>=0&&gx.x<n&&gx.y>=0&&gx.y<m) return true;
	return false;
}
int main ()
{
	while(~scanf("%d%d",&n,&m))
{
		dot gx;queue<dot>q;
		memset(vis,0,sizeof vis);
		for(int i = 0;i<n;i++)
		for(int j = 0;j<m;j++)
		cin>>mp[i][j];
		for(int i = 0;i<n;i++)
{
			for(int j = 0;j<m;j++)
{
				if(mp[i][j]=='r')
{
					gx.x = i;gx.y = j;gx.time = 0;
				}
				else if(mp[i][j]=='#') vis[i][j] = 1;
			}
		}
		q.push(gx);vis[gx.x][gx.y] = 1;int step = 0;
		while(!q.empty())
{
			dot tmp,nex;
			tmp = q.front(),q.pop();
			if(mp[tmp.x][tmp.y]=='x') ++tmp.time;
			for(int i = 0;i<4;i++)
{
				nex.x = tmp.x+dx[i];
				nex.y = tmp.y+dy[i];
				nex.time = tmp.time+1;
				if(in(nex)&&!vis[nex.x][nex.y])
{
					q.push(nex);vis[nex.x][nex.y] = 1;
					if(mp[nex.x][nex.y]=='a')
{
						step = nex.time;break;
					}
				}
			if(step>0) break;	
			}
		}
		if(step>0) printf("%d\n",step);
		else printf("Poor ANGEL has to stay in the * all his life.\n");
	}
	return 0;
}