DSA03005 - CHIA MẢNG THÀNH HAI MẢNG CON CÓ TỔNG LỚN NHẤT

//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 pii pair<int,int>
#define pll pair<ll,ll>
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);
    }
int n,k,a[N];
int main()
{
  ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
  int t=1;
  cin>>t;
  while(t--)
  {
     int s=0,ans=-1e9,t=0;
     cin>>n>>k;
     f1(i,n) cin>>a[i],s+=a[i];
     sort(a+1,a+n+1);
     f1(i,k) t+=a[i];
     ans=max(ans,abs(s-2*t));
     for(int i=k+1;i<=n;i++)
     {
         t=t+a[i]-a[i-k];
         ans=max(ans,abs(s-2*t));
     }
     cout<<ans;
     el;
  }
}
//-----YEU CODE HON CRUSH-----//