Minimize the sum of product

PROBLEM :
Given two arrays, A and B, of equal size n, the task is to find the minimum value  of A[0] * B[0] + A[1] * B[1] +…+ A[n-1] * B[n-1], where shuffling of elements of arrays A and B is allowed.

Examples:
Input : A[] = {3, 1, 1} and B[] = {6, 5, 4}.
Output : 23 Minimum value of S = 1*6 + 1*5 + 3*4 = 23.

Input : A[] = { 6, 1, 9, 5, 4 } and B[] = { 3, 4, 8, 2, 4 }
Output : 80. Minimum value of S = 1*8 + 4*4 + 5*4 + 6*3 + 9*2 = 80.


Input:
The first line of input contains an integer denoting the no of test cases. Then T test cases follow. Each test case contains three lines. The first line of input contains an integer N denoting the size of the arrays. In the second line are N space separated values of the array A[], and in the last line are N space separated values of the array B[].

Output:
For each test case in a new line print the required result.

Constraints:
1<=T<=100
1<=N<=50
1<=A[]<=20

Example:
Input:
2
3
3 1 1
6 5 4
5
6 1 9 5 4
3 4 8 2 4

Output:
23
80

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SIMPLE c++ IMPLEMENTATION :
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#include<iostream>
using namespace std;
#include<algorithm>
#define max 200
int main()
{
int arr1[max],arr2[max] ;
int n,t,i ;
cin>>t  ;
while(t--)
{
   cin>>n ;
   for(i=0;i<n;i++)
       cin>>arr1[i] ;
   for(i=0;i<n;i++)
       cin>>arr2[i] ;
     
   sort(arr1,arr1+n) ;
   sort(arr2,arr2+n,greater<int>()) ;
 
   int sum=0 ;
   for(i=0;i<n;i++)
       sum+=arr1[i]*arr2[i] ;

 
   cout<<sum<<endl ;
}
return 0;
}

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