HDU 4308 BFS+优先队列

#include <queue>
#include <stdio.h>
#include <iostream>
#include <string.h>
#include <stdlib.h>
#include <algorithm>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const int inf=0x3f3f3f3f;
const ll INF=0x3f3f3f3f3f3f3f3fll;
const int maxn=5010;
int n,m,k,sx,sy,ex,ey;
int dir[4][2]={{0,1},{0,-1},{1,0},{-1,0}};
bool vis[maxn][maxn];
char str[maxn][maxn];
struct edge{
int x,y,step,flag;
friend bool operator< (edge n1,edge n2)
{return n1.step>n2.step;}
};
struct pos{
int x,y;
pos(int a,int b){x=a;y=b;}
};
vector<pos>G;
int bfs(){
priority_queue<edge>que;
edge c,ne;
memset(vis,0,sizeof(vis));
c.x=sx,c.y=sy,c.step=0;
vis[c.x][c.y]=1;
que.push(c);
while(!que.empty()){
c=que.top();que.pop();
if(c.x==ex&&c.y==ey) return c.step;
if(str[c.x][c.y]=='P'){
int len=G.size();
for(int ll=0;ll<len;ll++){
pos ttt=G[ll];
if(vis[ttt.x][ttt.y]) continue;
ne.x=ttt.x;ne.y=ttt.y;ne.step=c.step;
vis[ne.x][ne.y]=1;
que.push(ne);
}
}
for(int i=0;i<4;i++){
int xx=c.x+dir[i][0];
int yy=c.y+dir[i][1];
if(xx<0||xx>n-1||yy<0||yy>m-1||str[xx][yy]=='#') continue;
if(vis[xx][yy]) continue;
ne.x=xx;ne.y=yy;ne.step=c.step;
if(str[xx][yy]=='*') ne.step+=k;
vis[ne.x][ne.y]=1;
que.push(ne);
}
}
return -1;
}
int main(){
while(scanf("%d%d%d",&n,&m,&k)!=-1){
G.clear();
for(int i=0;i<n;i++) scanf("%s",str[i]);
for(int i=0;i<n;i++){
for(int j=0;j<m;j++){
if(str[i][j]=='Y') sx=i,sy=j;
if(str[i][j]=='C') ex=i,ey=j;
if(str[i][j]=='P') G.push_back(pos(i,j));
}
}
int ans=bfs();
if(ans==-1) printf("Damn teoy!\n");
else printf("%d\n",ans);
}
return 0;
}