Inverse Inversions

1#include <bits/stdc++.h>
2using namespace std;
3#define int long long
4
5signed main(){
6  ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
7  int n,k; cin>>n>>k;
8  int res[n],l=1,r=n;
9  for(int i=0;i<n;++i){
10    if(k>=n-i-1) res[i]=r--,k-=n-i-1;
11    else res[i]=l++;
12  }
13  for(auto&x:res) cout<<x<<" "; cout<<'\n';
14  return 0;
15}