bfs

不想多说，就bfs爆搜，写起来挺麻烦的，不需要方向数组，不需要设置偏移量

#include<bits/stdc++.h>
using namespace std;
const int N = 1010;
struct loc{
    double x,y,z;
}a[N];
int st[N];
int n,h,r;
queue<loc> q;
double dist(loc l1,loc l2)
{
    double dx=l1.x-l2.x,  dy=l1.y-l2.y,  dz=l1.z-l2.z;
    return sqrt((dx*dx)+(dy*dy)+(dz*dz));
}
int bfs(void)
{
    while(!q.empty())
    {
        loc u=q.front();
        if(u.z+r>=h)return true;
        q.pop();
        for(int i=1;i<=n;i++)
        {
            if(st[i]==0&&dist(u,a[i])<=2*r)
            {
                st[i]=1;
                q.push(a[i]);
                if(a[i].z+r>=h)
                {
                    return true;
                }
            }
        }
    }
    return false;
}
int main()
{
    int t;
    cin>>t;
    while(t--)
    {
        memset(st, 0, sizeof st);
        while(!q.empty())q.pop();
        cin>>n>>h>>r;
        for(int i=1;i<=n;i++)
        {
            cin>>a[i].x>>a[i].y>>a[i].z;
            if(a[i].z<=r)
            {
                q.push(a[i]);
                st[i]=1;
            }
        }
        if(bfs())cout<<"Yes"<<endl;
        else cout<<"No"<<endl;
    }
    return 0;
}