Tanssiaiset

input/code.cpp: In function 'int main()':
input/code.cpp:27:9: warning: 'b' may be used uninitialized in this function [-Wmaybe-uninitialized]
         if (b == i) cout<<a<<" "<<b<<endl, exit(0);
         ^

#include <bits/stdc++.h>

using namespace std;

int u[100001];
vector<int> v[100001];

int main () {
    int n;
    cin>>n;
    for (int i = 0; i <= n / 2; i++) {
        int a, b;
        cin>>a>>b;
        u[a]++;
        u[b]++;
        v[a].push_back(b);
    }
    int a, b;
    a = -1;
    for (int i = 1; i <= n; i++) {
        if (u[i] == 2) {
            if (a == -1) a = i;
            else b = i;
        }
    }
    for (int i : v[a]) {
        if (b == i) cout<<a<<" "<<b<<endl, exit(0);
    }
    cout<<b<<" "<<a<<endl;
}

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: ACCEPTED