(HDU1242)Rescue

任意门：http://acm.hdu.edu.cn/showproblem.php?pid=1242

#include<iostream>#include<cstdio>#include<algorithm>#include<cmath>#include<cstring>#include<string>#include<sstream>#include<set>#include<fstream>#include<iomanip>#include<queue>#define M 222int n,m,a,b,X,Y;int vis[M][M];char ma[M][M];int dir[4][2]={0,1,0,-1,1,0,-1,0};struct state{    int x,y,step;    friend bool operator<(state x1,state x2){        return x1.step>x2.step;  //优先队列，按照步数从小到大排列（最小优先队列）    }};bool check(int x,int y){    if(x<0||y<0||x>=n||y>=m||vis[x][y]||ma[x][y]=='#')        return 1;    return 0;}int BFS(){    priority_queue <state> Q;    state st,next;    st.x=a;    st.y=b;    st.step=0;    Q.push(st);    vis[a][b]=1;    while(!Q.empty())    {        st=Q.top();        Q.pop();        if(st.x==X&&st.y==Y)            return st.step;        for(int i=0;i<4;i++)        {            next.x=st.x+dir[i][0];            next.y=st.y+dir[i][1];            if(check(next.x,next.y))                continue;            if(!vis[next.x][next.y]){                vis[next.x][next.y]=1;                if(ma[next.x][next.y]=='x')                    next.step=st.step+2;                else                    next.step=st.step+1;                Q.push(next);            }        }    }    return 0;}int main(){    while(~scanf("%d%d",&n,&m)&&n&&m)    {        memset(vis,0,sizeof(vis));        for(int i=0;i<n;i++){            for(int j=0;j<m;j++){                cin>>ma[i][j];                if(ma[i][j]=='r')                {a=i;b=j;}                if(ma[i][j]=='a')                {X=i;Y=j;}            }        }        int ans=BFS();        if(ans)            cout<<ans<<endl;        else cout<<"Poor ANGEL has to stay in the prison all his life."<<endl;    }    return 0;}