HackerEarth Top contestants problem solution

#include<bits/stdc++.h>
using namespace std;

int main(){
    int n,k;
    cin>>n>>k;
    assert(n>=1 && n<=100000);
    assert(k>=1 && k<=n);
    pair<int,int> arr[n+1];
    for(int i=0;i<n;i++){
        int val;
        cin>>val;
        assert(val>=1 && val<=1000000000);
        arr[i].first=val;
        arr[i].second=i+1;
    }
    sort(arr,arr+n);
    for(int i=n-1;i>=n-k;i--) cout<<arr[i].second<<" ";
    return 0;
}