HDU 4308 Contest 1

纯BFS+优先队列扩展。

 #include <iostream>
 #include <cstdio>
 #include <cstring>
 #include <string.h>
 #include <queue>
 using namespace std;
 
 bool vis[5100];
 char str[5100];
 
 struct point{
 	int x,y;
 	int cost;
 	bool operator < (const point &a)const{
 		return cost>a.cost;
 	}
 }st,en,passort[550],tmp,pushed;
 int pp;
 priority_queue<point>que;
 int dir[4][2]={
 	{0,1},{0,-1},{1,0},{-1,0}
 };
 
 
 int work(int r,int c,int cost){
 	memset(vis,false,sizeof(vis));
 	int x,y;
 	st.cost=0;
 	que.push(st);
 	vis[st.x*c+st.y]=true;
 	while(!que.empty()){
 		tmp=que.top();
 		que.pop();
 		for(int i=0;i<4;i++){
 			x=tmp.x+dir[i][0],y=tmp.y+dir[i][1];
 			if(x>=0&&x<r&&y>=0&&y<c){
 				if(str[x*c+y]!='#'&&!vis[x*c+y]){
 					if(str[x*c+y]=='*'){
 						pushed.x=x;
 						pushed.y=y;
 						pushed.cost=tmp.cost+cost;
 						que.push(pushed);
 						vis[x*c+y]=true;
 					}
 					else if(str[x*c+y]=='P'){
 						for(int ps=0;ps<pp;ps++){
 							pushed.x=passort[ps].x;
 							pushed.y=passort[ps].y;
 							pushed.cost=tmp.cost;
 							que.push(pushed);
 							vis[x*c+y]=true;
 						}
 					}
 					else if(str[x*c+y]=='C')
 					return tmp.cost;
 				}
 			}
 		}
 	}
 	return -1;
 }
 
 int main(){
 	int r,c,cost;
 	while(scanf("%d%d%d",&r,&c,&cost)!=EOF){
 		getchar();
 		int beg=0;
 		pp=0;
 		for(int i=0;i<r;i++){
 			gets(str+beg);
 			for(int k=beg;k<beg+c;k++)
 			if(str[k]=='Y'){
 				st.x=i;
 				st.y=k-beg;
 			}
 			else if(str[k]=='C'){
 				en.x=i;
 				en.y=k-beg;
 			}
 			else if(str[k]=='P'){
 				passort[pp].x=i;
 				passort[pp].y=k-beg;
 				pp++;
 			}
 			beg+=c;
 		}
 		int ans=work(r,c,cost);
 		if(ans==-1) printf("Damn teoy!
");
 		else
 		printf("%d
",ans);
 		while(!que.empty())
 		que.pop();
 	}
 	return 0;
 }