CSES – Josephus Problem II

#include<bits/stdc++.h>
#define pii pair<int,int>
#define f first
#define s second
#define fastio ios_base::sync_with_stdio(0);cin.tie(0)
using namespace std;
//declare
#include<ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> order_set;
int n,k;
//
signed main(){
    fastio;
    cin>>n>>k;
    int idx = k % n, cur;
    for(int i=1;i<=n;i++) order_set.insert(i);
    while(n --> 1){
        int cur = *order_set.find_by_order(idx);
        cout<<cur<<" ";
        order_set.erase(cur);
        idx = (idx + k) % n;
    }
    cout<<*order_set.begin()<<"\n";
    return 0;
}