Astralis session I

input/code.cpp: In function 'int main()':
input/code.cpp:48:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   48 |     for (int i = 0; i < e.size(); ++i){
      |                     ~~^~~~~~~~~~

using namespace std;

#include <iostream>
#include <algorithm>
#include <vector>
#include <utility>
#include <unordered_set>  


int dfs(vector< unordered_set<int> >&e, int k, int parent){
    int sum = 1;
    for (auto i = begin(e[k]); i != end(e[k]); ++i) {
        if (*i != parent)
            sum += dfs(e, (*i), k);
    }
    return sum;
}

void dfs_print(vector< unordered_set<int> >&e, int k, int parent, char letter){
    cout << letter;
    for (auto i = begin(e[k]); i != end(e[k]); ++i) {
        if (*i != parent)
            dfs_print(e, (*i), k, letter);
    }
}


int main(){

    int n;

    cin >> n;

    vector< unordered_set<int> > adj = vector<unordered_set<int> >(n+1);
    vector< pair<int, int> > e;
    for (int i = 0; i < n-1; ++i)
    {
        int aux1, aux2;

        cin >> aux1 >> aux2;

        adj[aux1].insert(aux2);
        adj[aux2].insert(aux1);
        
        e.push_back(make_pair(aux1, aux2));
    }

    for (int i = 0; i < e.size(); ++i){
        int v1 = e[i].first;
        int v2 = e[i].second;
        
        adj[v1].erase(v2);
        adj[v2].erase(v1);

        if (dfs(adj, v1, -1) == dfs(adj, v2, -1))
        {
            cout << "Yes" << endl;
            dfs_print(adj, v1, -1, 'U');
            dfs_print(adj, v2, -1, 'M');
            cout << endl;
            return 0;
        }

        adj[v1].insert(v2);
        adj[v2].insert(v1);
    }

    cout << "No" << endl;

}   

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: WRONG ANSWER

Test 6

Verdict: WRONG ANSWER

Test 7

Verdict: WRONG ANSWER

Test 8

Verdict: ACCEPTED

Test 9

Verdict: WRONG ANSWER

Test 10

Verdict: WRONG ANSWER

Test 11

Verdict: ACCEPTED

Test 12

Verdict: WRONG ANSWER

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: WRONG ANSWER

Test 16

Verdict: WRONG ANSWER

Test 17

Verdict: ACCEPTED

Test 18

Verdict: WRONG ANSWER

Test 19

Verdict: WRONG ANSWER

Test 20

Verdict: ACCEPTED

Test 21

Verdict: ACCEPTED

Test 22

Verdict: WRONG ANSWER

Test 23

Verdict: WRONG ANSWER

Test 24

Verdict: WRONG ANSWER

Test 25

Verdict: WRONG ANSWER

Test 26

Verdict: ACCEPTED

Test 27

Verdict: ACCEPTED

Test 28

Verdict: WRONG ANSWER

Test 29

Verdict: ACCEPTED

Test 30

Verdict: ACCEPTED

Test 31

Verdict: WRONG ANSWER

Test 32

Verdict: WRONG ANSWER

Test 33

Verdict: ACCEPTED

Test 34

Verdict: WRONG ANSWER

Test 35

Verdict: ACCEPTED

Test 36

Verdict: WRONG ANSWER

Test 37

Verdict: WRONG ANSWER

Test 38

Verdict: WRONG ANSWER

Test 39

Verdict: WRONG ANSWER

Test 40

Verdict: ACCEPTED

Test 41

Verdict: WRONG ANSWER

Test 42

Verdict: WRONG ANSWER

Test 43

Verdict: ACCEPTED

Test 44

Verdict: ACCEPTED

Test 45

Verdict: ACCEPTED

Test 46

Verdict: WRONG ANSWER

Test 47

Verdict: WRONG ANSWER

Test 48

Verdict: ACCEPTED

Test 49

Verdict: WRONG ANSWER

Test 50

Verdict: WRONG ANSWER

Test 51

Verdict: WRONG ANSWER

Test 52

Verdict: TIME LIMIT EXCEEDED

Test 53

Verdict: WRONG ANSWER

Test 54

Verdict: WRONG ANSWER

Test 55

Verdict: WRONG ANSWER

Test 56

Verdict: TIME LIMIT EXCEEDED

Test 57

Verdict: WRONG ANSWER

Test 58

Verdict: WRONG ANSWER

Test 59

Verdict: WRONG ANSWER

Test 60

Verdict: WRONG ANSWER

Test 61

Verdict: TIME LIMIT EXCEEDED