Easy Going_hackker_earth

#include<iostream>
#include<math.h>
using namespace std;


//Ham Hoan Vi
void HoanVi(int &a,int &b)
{
    int t = a;
    a = b;
    b= t;
}
//Ham sap xep = bubble sort
void BubbleSort(int a[],int n)
{
    for (int i = 0; i < n-1; i++)
    {
        int flag = 0;
        for (int j = 0; j < n; j++)
        {
            if(a[j] > a[j+1])
            {
                HoanVi(a[j],a[j+1]);
                flag++;
            }
        }
        if (flag == 0)
        {
            break;
        }
    }
}
//Ham nhap mang
void Nhap(int a[],int n)
{
    for(int i = 0; i < n;i++)
    {
        cin>>a[i];
    }
}
//Ham tinh toan
int Kq(int a[],int n,int m)
{
    int sum1 =0 ,sum2 = 0;
    for (int i = 0; i < n-m; i++)
    {
        sum1+= a[i];
    }
    for (int i = n-1; i >= m; i--)
    {
        sum2+= a[i];
    }
    return (sum2-sum1);
}
int main()
{
    int t;
    cin>>t;
    while (t--)
    {
        int n,m;
        cin>>n;
        cin>>m;
        int *a = new int [n];
        Nhap(a,n);
        BubbleSort(a,n);
        int kq = Kq(a,n,m);
        cout<<abs(kq)<<endl;

        delete[] a;
    }

    return 0;
}