Urkupillit

#include <iostream>
#include <string>
#include <cmath>
#include <cstdio>
#include <algorithm>

using namespace std;

typedef long long int ll;

ll n, k;
ll output = 0;

ll outputNeeded(ll i) {
	// cout << "adding " << i << " pairs.." << endl;
	ll high = (1+sqrt(1+8*i))/2;
	// cout << "\thigh: " << high << endl;
	ll num = (high*(high-1)) / 2;
	// cout << "\tnumber of creatable pairs: " << num << endl;
	for (ll k = 0; k < high; ++k) {
		cout << output + high - k << " ";
	}
	output += high;
	return num;
}

int main() {

	ios_base::sync_with_stdio(false);

	cin >> n >> k;

	ll s = k;
	while (s > 0) {
		s -= outputNeeded(s);
	}

	while (output < n) {
		++output;
		cout << output << " ";
	}
	cout << '\n';

	return 0;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: WRONG ANSWER

Test 11

Group: 3

Verdict: ACCEPTED

Test 12

Group: 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: ACCEPTED

Test 14

Group: 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: ACCEPTED