DSA03007 - GIÁ TRỊ NHỎ NHẤT CỦA BIỂU THỨC

//Made By Phuong Nam PROPTIT <3//
#pragma GCC Optimize("O3")
#include<bits/stdc++.h>
#include<string>
#include<vector>
#define alphaa "abcdefghijklmnopqrstuvwxyz"
#define ALPHAA "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
#define f(i,a,b) for(int i=a;i<=b;i++)
#define f1(i,n) for(int i=1;i<=n;i++)
#define f0(i,n) for(int i=0;i<n;i++)
#define ff(i,b,a) for(int i=b;i>=a;i--)
#define el cout<<'\n'
#define fi first
#define se second
#define pb push_back
#define pk pop_back
#define vi vector<int>
#define vl vector<ll>
#define pii pair<int,int>
#define pll pair<ll,ll>
#define all(s) s.begin(),s.end()
using namespace std;
typedef long long ll;
const int N=1e6+3;
const int MOD=1e9+7;
template<class X,class Y>
    void minimize(X &x,const Y &y) {
        if (x>y) x=y;
    }
template<class X,class Y>
    void maximize(X &x,const Y &y) {
        if (x<y) x=y;
    }
template<class T>
    T Abs(const T &x) {
        return (x<0?-x:x);
    }
ll tinh1(ll a[],ll b[],int n)
{
    sort(a,a+n);
    sort(b,b+n);
    ll s=0;
    f0(i,n) s+=a[i]*b[i];
    return s;
}
ll tinh2(ll a[],ll b[],int n)
{
    sort(a,a+n);
    sort(b,b+n,greater<ll>());
    ll s=0;
    f0(i,n) s+=a[i]*b[i];
    return s;
}
ll tinh3(ll a[],ll b[],int n)
{
    sort(a,a+n,greater<ll>());
    sort(b,b+n);
    ll s=0;
    f0(i,n) s+=a[i]*b[i];
    return s;
}
ll tinh4(ll a[],ll b[],int n)
{
    sort(a,a+n,greater<ll>());
    sort(b,b+n,greater<ll>());
    ll s=0;
    f0(i,n) s+=a[i]*b[i];
    return s;
}
void xuly()
{
    int n;
    cin>>n;
    ll a[n],b[n];
    f0(i,n) cin>>a[i];
    f0(i,n) cin>>b[i];
    ll t1=tinh1(a,b,n);
    ll t2=tinh2(a,b,n);
    ll t3=tinh3(a,b,n);
    ll t4=tinh4(a,b,n);
    cout<<min(min(t1,t2),min(t2,t3));
    el;
}
int main()
{
  ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
  int t=1;
  cin>>t;
  while(t--) xuly();
  return 0;
}
//-----YEU CODE HON CRUSH-----//