Help me in solving SUBS problem

help
,
1

My issue

My logic : Sort the array and just output diff of kth element and first element.
Can’t figure out why this doesn’t work

My code

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define nl "\n"
#define maxe(a) (*max_element(a.begin(), a.end()))
#define mine(a) (*min_element(a.begin(), a.end()))
#define all(a) a.begin(), a.end()
#define nsb(n) (__builtin_popcountll(n))  //no of set bits.
#define len(n) (to_string(n).size())
#define is2pow(n) (n && (!(n&(n-1))))


int main(){

  ios_base::sync_with_stdio(false);
  cin.tie(NULL);

 // #ifndef ONLINE_JUDGE
  // freopen("input.txt","r",stdin);
  // freopen("output.txt","w",stdout);
  // #endif



// code here
int t;
cin>>t;

while(t--){
  ll n,k;
  cin>>n>>k;
  
  vector<ll> v(n);
  for(int i=0 ; i<n ; i++){
    cin>>v[i];
  }
  
  sort(all(v));
  
  cout<<v[k-1] - v[0]<<nl;
  
}





  return 0;

}

Learning course: Jump from 2* to 3*
Problem Link: CodeChef: Practical coding for everyone

2

@yashjoshi6787
for test case
1
4 2
1 3 4 5
your code will print 2 but correct answer would be 1 choosing [4,5].

3

ohh right . Thanks !