Distinct sums

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

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	int n;
	cin >> n;

	if (n % 2) {
		cout << "IMPOSSIBLE" << endl;
		return 0;
	}

	cout << "YES" << endl;

	for (int i = 0; i < n; ++i) {
		for (int j = 0; j < n; ++j) {
			if (j < i) {
				cout << 2 << " ";
			} else if (j % 2 == 1 && i == j) {
				cout << 1 << " ";
			} else {
				cout << 0 << " ";
			}
		}
		cout << endl;
	}
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED