算距离的时候平方炸`int`了，改成`long long`就过了
```cpp
#include<bits/stdc++.h>
#define N 5005
using namespace std;
struct xx{double x,y,z;}a[N];
int k,n,i,j,tot,q[N],vis[N],head[N],son[N],nxt[N];
double h,r;
inline void add(int x,int y){son[++tot]=y;nxt[tot]=head[x];head[x]=tot;}
inline bool dist(int i,int j){
long long xx=(a[i].x-a[j].x)*(a[i].x-a[j].x);
long long yy=(a[i].y-a[j].y)*(a[i].y-a[j].y);
long long zz=(a[i].z-a[j].z)*(a[i].z-a[j].z);
return (xx+yy+zz)<=4ll*r*r;
}
int main(){
scanf("%d",&k);
while(k--){
scanf("%d%lf%lf",&n,&h,&r);
tot=0;
for(i=0;i<=n+1;i++)head[i]=vis[i]=0;
for(i=1;i<=n;i++){
scanf("%lf%lf%lf",&a[i].x,&a[i].y,&a[i].z);
if(a[i].z<=r)add(0,i),add(i,0);
if(a[i].z+r>=h)add(i,n+1),add(n+1,i);
}
for(i=1;i<=n;i++)
for(j=i+1;j<=n;j++)
if(dist(i,j))add(i,j),add(j,i);
int h=1,t=1,flag=0;q[1]=0;vis[0]=1;
while(h<=t){
int x=q[h];
for(i=head[x];i;i=nxt[i]){
int v=son[i];
if(vis[v])continue;
if(v==n+1){flag=1;break;}
q[++t]=v;vis[v]=1;
}
if(flag)break;h++;
}
if(flag)printf("Yes\n");
else printf("No\n");
}
}
```
by libohan0905 @ 2022-11-12 09:24:35
@[libohan0905](/user/205125)
为什么还是40分呢？
by louzhengzhe2009 @ 2022-11-18 18:49:19
可以过的，仔细看我给的代码，**把你的`dist`函数里的`4.0`改为`4LL`就好了，注意数字也要开`long long`** @[louzhengzhe2009](/user/770104)
by libohan0905 @ 2022-11-20 13:22:09
[评测记录](https://www.luogu.com.cn/record/94769300)
by libohan0905 @ 2022-11-20 13:22:45
@[libohan0905](/user/205125) 那咋回事？
[评测记录](https://www.luogu.com.cn/record/94846234)
by louzhengzhe2009 @ 2022-11-20 20:00:18
别开O2就A了
by libohan0905 @ 2022-11-20 20:05:39
貌似把$N$开大（比如$100005$）开O2也能A
by libohan0905 @ 2022-11-20 20:07:22
@[louzhengzhe2009](/user/770104)
by libohan0905 @ 2022-11-20 20:10:05
@[libohan0905](/user/205125) 谢谢！没开O2过了！
by louzhengzhe2009 @ 2022-11-20 21:17:59
@[libohan0905](/user/205125) 不过为什么开了O2只有40分呢？
by louzhengzhe2009 @ 2022-11-20 21:18:36