#include<iostream>
#include<cstdio>
#include<set>
#include<vector>
#include<algorithm>
#include<stack>
#include<queue>
#include<cmath>
#include<string>
#include<cstring>
#include<cstdlib>
#include
<map>
using namespace std;
#define scan(n) scanf("%d",&n)
#define ll long long
const ll mod = 10007;
const int maxn = 1e6+10;
const int INF=0x3f3f3f3f;
double cost[1010][1010],lowc[2010],ans;
int n,m;
bool vis[3010];
double Max[1010][1010];
int pre[2020];
bool used[1010][1010];
double prim(){
double ans = 0;
memset(vis,false,sizeof(vis));
memset(Max,0,sizeof(Max));
memset(used,0,sizeof(used));
vis[0]=true;
pre[0]=-1;
for(int i=1;i<n;i++){
lowc[i]=cost[0][i];
pre[i]=0;
}
lowc[0]=0.0;
for(int i=1;i<n;i++){
double minc = INF;
int p=-1;
for(int j=0;j<n;j++){ if(!vis[j]&&minc>lowc[j]){
minc=lowc[j];
p=j;
}
}
if(minc==INF)return -1;
ans += minc;
vis[p]=true;
used[p][pre[p]]=used[pre[p]][p]=true;
for(int j=0;j<n;j++){ if(vis[j] && j!=p)Max[j][p]=Max[p][j]=max(Max[j][pre[p]],lowc[p]); if(!vis[j] && lowc[j]>cost[p][j]){
lowc[j] = cost[p][j];
pre[j]=p;
}
}
}
cout<<ans<<endl;
return ans;
}
double x[2010],y[2010],z[2010];
int main(){
int t;
scanf("%d", &t);
while(t--){
scanf("%d", &n);
for(int i=0;i<n;i++){
scanf("%lf%lf%lf", &x[i],&y[i],&z[i]);
}
for(int i=0;i<n;i++){
for(int j=i+1;j<n;j++){
cost[i][j] = cost[j][i] = sqrt((x[i]-x[j])*(x[i]-x[j])+(y[i]-y[j])*(y[i]-y[j]));
}
}
double ans1 = prim();
double maxx=0.0;
for(int i=0;i<n;i++){
for(int j=i+1;j<n;j++){
maxx = max(maxx,(z[i]+z[j])/(ans1-Max[i][j]));
}
}
printf("%.2f\n", maxx);
}
return 0;
}
撰写