[NOIp2017 Cheese]

NOIp2017 Cheese

那么长时间了,,,,后天就要去华师参加夏令营了...然而今天才做出来这道题...
就是一个搜索.

#include <cstring>
#include <cstdio>
#include <queue>
#include <cmath>
using namespace std;
const int MAXN=1e3+1;
double x[MAXN],y[MAXN],z[MAXN];
bool vis[MAXN];
queue<int>q;
double dist(int u,int v)
{
	double dx=x[u]-x[v],dy=y[u]-y[v],dz=z[u]-z[v];
	return sqrt(dx*dx+dy*dy+dz*dz);
}
int main()
{
	int t;scanf("%d",&t);
	while(t--)
	{
		memset(vis,0,sizeof(vis));
		while(!q.empty())q.pop();
		int n,h,is=0;double r;
		scanf("%d %d %lf",&n,&h,&r);
		for(int i=1;i<=n;i++)
		{
			scanf("%lf %lf %lf",&x[i],&y[i],&z[i]);
			if(z[i]+r>=h && z[i]-r<=0)is=1;
			if(z[i]-r<=0){
				q.push(i);
				vis[i]=true;
			}
		}
		while(!q.empty()){
			int u=q.front();q.pop();
			if(z[u]+r>=h){
				is=1;break;
			}
			for(int v=1;v<=n;v++){
				if(v!=u && !vis[v] && dist(u,v)<=r*2){
					vis[v]=true;
					q.push(v);
				}
			}
		}
		if(is==1)printf("Yes\n");
		else printf("No\n");
	}
	return 0;
}