[NOIP 2017] 奶酪

[题目链接]

         http://uoj.ac/problem/332

[算法]

         直接搜索即可

         注意使用long long

[代码]

        

#include<bits/stdc++.h>
using namespace std;
#define MAXN 1010
#define dist(x1,y1,z1,x2,y2,z2) sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2) + (z1 - z2) * (z1 - z2))

struct info
{
        long long x,y,z;
} a[MAXN];

int i,T;
long long n,h,r;
bool ok;
bool visited[MAXN];

inline void dfs(int now)
{
        int i;
        if (h - a[now].z <= r) 
        {
                ok = true;
                return;    
        }                
        visited[now] = true;
        for (i = 1; i <= n; i++)
        {
                if (!visited[i] && dist(a[now].x,a[now].y,a[now].z,a[i].x,a[i].y,a[i].z) <= 2 * r)
                        dfs(i);
        }
} 
 
int main() 
{
        
        scanf("%d",&T);
        while (T--)
        {
                scanf("%lld%lld%lld",&n,&h,&r);
                for (i = 1; i <= n; i++) scanf("%lld%lld%lld",&a[i].x,&a[i].y,&a[i].z);
                memset(visited,false,sizeof(visited));
                ok = false;
                for (i = 1; i <= n; i++)
                {
                        if (!visited[i] && a[i].z <= r)    
                                dfs(i);
                        if (ok) break;
                }        
                if (ok) printf("Yes\n");
                else printf("No\n");
        }
        
        return 0;
    
}