func_code_string: #include <bits/stdc++.h>   using namespace std;       int main(){       int t,n;       scanf( %d ,&t);       while(t--){           scanf( %d ,&n); double ans=0;           vector<double>miners; vector<double>diamonds;           for(int i=0;i<2*n;i++){              double a,b;               scanf( %lf%lf ,&a,&b);               if (a==0){miners.push_back(abs(b));}               if (b==0){diamonds.push_back(abs(a));}           }           sort(miners.begin(),miners.end());           sort(diamonds.begin(),diamonds.end());           for (int i=0;i<n;i++){               ans+=sqrt(miners[i]*miners[i]+diamonds[i]*diamonds[i]);           }           printf( %.15lf n ,ans);       }       return 0;   }