hdu 1242 BFS

//直接从a向r搜索，不需要用优先队列
#include <iostream>
#include <queue>
#include <cstring>
using namespace std;

typedef struct
{
int x;
int y;
int step;
}point;

int N,M;
char map[205][205];
bool visited[205][205];
int s_x,s_y;
int dirX[4] = {-1,0,1,0};
int dirY[4] = {0,1,0,-1};
bool flag;

int BFS()
{
point p;
p.x = s_x;
p.y = s_y;
visited[p.x][p.y] = true;
p.step = 0;
queue<point> Q;
Q.push(p);
while(!Q.empty())
{
point q;
q = Q.front();
Q.pop();

for(int i = 0; i < 4; i++)
{
point t;
t.x = q.x + dirX[i];
t.y = q.y + dirY[i];

if(t.x < 0 || t.x >= N || t.y < 0 || t.y >= M || map[t.x][t.y] == '#' || visited[t.x][t.y])
{
continue;
}
visited[t.x][t.y] = true;
if(map[t.x][t.y] == 'r')
{
flag = true;
t.step = q.step + 1;
return t.step;
}

if(map[t.x][t.y] == '.')
{
t.step = q.step + 1;
Q.push(t);
}
if(map[t.x][t.y] == 'x')
{
t.step = q.step + 2;
Q.push(t);
}

}
}
return 0;
}

int main()
{
while(cin>>N>>M)
{
for(int i = 0; i < N; i++)
{
for(int j = 0; j < M; j++)
{
cin>>map[i][j];
if(map[i][j] == 'a')
{
s_x = i;
s_y = j;
}
}
}
memset(visited,false,sizeof(visited));
flag = false;
int ans = BFS();
if(flag)
{
cout<<ans<<endl;
}
else
{
cout<<"Poor ANGEL has to stay in the prison all his life."<<endl;
}

}
return 0;
}