Building Teams

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

int main() {
    int n, m;
    cin >> n >> m;
    int t1, t2;
    int v2[n][n];
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            v2[i][j] = 0;
        }
    }
    for (int i = 0; i < m; i++) {
        cin >> t1 >> t2;
        v2[t1 - 1][t2 - 1] = 1;
    }

    vector<int> ans;
    for (int i = 0; i < n; i++) {ans.push_back(1);}
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            if (!v2[i][j]) continue;
            if (ans[i] != ans[j]) continue;
            else if (ans[j] == 1 && ans[i] == 1) {
                ans[j] = 2;
            }
            else if (ans[j] == 2 && ans[i] == 2) {
                cout << "IMPOSSIBLE";
                return 0;
            }
        }
    }


    for (int i = 0; i < n; i++) {
        cout << ans[i];
        if (i == n - 1) continue;
        else cout << ' ';
    }
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: WRONG ANSWER

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: RUNTIME ERROR

Test 7

Verdict: RUNTIME ERROR

Test 8

Verdict: RUNTIME ERROR

Test 9

Verdict: RUNTIME ERROR

Test 10

Verdict: RUNTIME ERROR

Test 11

Verdict: WRONG ANSWER

Test 12

Verdict: ACCEPTED