题目链接：点击打开链接http://acm.hdu.edu.cn/showproblem.php?pid=1242
#include <stdio.h>
#include <string.h>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
using namespace std;
const int N=220;
int n,m,stx,sty,endx,endy;
char mp[N][N];
int vis[N][N];
int f[4][2]={{0,-1},{-1,0},{0,1},{1,0}};//keng
struct node
{
int x;
int y;
int t;
friend bool operator < (const node &a,const node &b)
{
return a.t>b.t;//大于是从小往大排
}
} ;
bool isbound(int x,int y)
{
if(x>0&&x<=n&&y>0&&y<=m&&mp[x][y]!='#')
return true;
else
return false;
}
void BFS(int x,int y)
{
priority_queue<node>Q;
memset(vis,0,sizeof(vis));
while(!Q.empty())
{
Q.pop();
}
node p,q;
p.x=x;
p.y=y;
p.t=0;
vis[p.x][p.y]=1;
Q.push(p);
while(!Q.empty())
{
p=Q.top();
Q.pop() ;
if(p.x==endx&&p.y==endy)
{
printf("%d
",p.t);
return;
}
for(int i=0;i<4;i++)
{
q.x=p.x+f[i][0];
q.y=p.y+f[i][1];
if(!isbound(q.x,q.y)) continue;
if(vis[q.x ][q.y ]==1) continue;
vis[q.x ][q.y]=1;
if(mp[q.x ][q.y]=='x')
q.t =p.t + 2;
else
q.t =p.t + 1;
Q.push(q);
}
}
printf("Poor ANGEL has to stay in the prison all his life.
");
}
int main()
{
while(~scanf("%d%d",&n,&m))
{
for(int i=1;i<=n;i++)
{
for(int j=1;j<=m;j++)
{
cin>>mp[i][j];
if(mp[i][j]=='r')
{
stx=i;
sty=j;
}
else if(mp[i][j]=='a')
{
endx=i;
endy=j;
}
}
}
BFS(stx,sty);
}
return 0;
}