Summat

#include <iostream>
#include <set>
#include <vector>
 
using namespace std;
 
int main()
{
	int n;
	cin >> n;
	multiset<int> in;
	for (int i = 0; i < n*(n-1)/2; ++i) {
		int v;
		cin >> v;
		in.insert(v);
	}
	int ab = *in.begin() + *next(in.begin());
	vector<int> A(n);
	for (auto k = next(in.begin(), 2); k != in.end(); ++k) {
		A[0] = (ab - *k) / 2;
		multiset<int> B = in;
		bool fail = false;
		for (int i = 1; i <= n; ++i) {
			for (int j = 0; j < i - 1; ++j) {
				int x = A[j] + A[i-1];
				auto it = B.find(x);
				if (it == B.end()) {
					fail = true;
					break;
				}
				B.erase(it);
			}
			if (fail) break;
			if (i == n) break;
			A[i] = *B.begin() - A[0];
		}
		if (fail) {
			++A[0];
		} else {
			break;
		}
	}
 
	for (int i = 0; i < n - 1; ++i) {
        	cout << A[i] << " "; 
	}
	cout << A[n-1] << endl;
}

Test 1

Group: 1, 2, 3

Verdict: ACCEPTED

Test 2

Group: 1, 2, 3

Verdict: ACCEPTED

Test 3

Group: 1, 2, 3

Verdict: ACCEPTED

Test 4

Group: 1, 2, 3

Verdict: ACCEPTED

Test 5

Group: 1, 2, 3

Verdict: ACCEPTED

Test 6

Group: 2, 3

Verdict: ACCEPTED

Test 7

Group: 2, 3

Verdict: ACCEPTED

Test 8

Group: 2, 3

Verdict: ACCEPTED

Test 9

Group: 2, 3

Verdict: ACCEPTED

Test 10

Group: 2, 3

Verdict: ACCEPTED

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