90pts求调

#include <bits/stdc++.h>
using namespace std;
    
double n,x[15],y[15],minn = 1e9;
bool f[15];
    
void dfs(int step,double c,double last1,double last2)
{
    if (step > n)
    {
        minn = min(minn,c);
        return ;
    }
    for (int i = 1;i <= n;i++)
    {
        if (!f[i] && c < minn)
        {
            f[i] = 1;
            dfs(step + 1,c + sqrt((last1 - x[i]) * ((last1 - x[i])) + (last2 - y[i]) * (last2 - y[i])),x[i],y[i]);
            f[i] = 0;
        }
    }
}

int main()
{
    cin >> n;
    for (int i = 1;i <= n;i++)
    {
        cin >> x[i] >> y[i];
    }
    dfs(1,0,0,0);
    printf("%.2lf\n",minn);
    return 0;
}