Astralis session I

// ~/.vim/cpp_template.cpp
#include <bits/stdc++.h>
#include <iostream>
#include <vector>
#include <algorithm>
#include <string>

#define REP(i,a,b) for (int i = a; i < b; i++)

using namespace std;

template <typename T>
void pV(const std::vector<T>& vec, const std::string& label = "Vector") {
    std::cout << label << ": [ ";
    for (const auto& elem : vec) {
        std::cout << elem << " ";
    }
    std::cout << "]" << std::endl;
}


int dfs(int s, vector<bool> *visited, vector<int> (*adj)[]) {
    if ((*visited)[s]) return 0;
    (*visited)[s] = true;
    // process node s
    int res = 1;


    for (auto u: (*adj)[s]) {
        res += dfs(u, visited, adj);
    }
    return res;
}


int getMaxDegree(int N, vector<int> (*adj)[]) {
    int maxDegree = 0;
    for (int i = 0; i < N; i++) {
        int degree = (*adj)[i].size();
        maxDegree = max(maxDegree, degree); 
    }
    return maxDegree;
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    // Your code starts here
    int N;
    cin >> N;

    if(N%2 == 1){
        cout << "No" << endl;
    }
    
    vector<int> adj[N];
    int u, v;
    for(int i = 0; i < N-1;i++){
        cin >> u >> v;
        u--;
        v--;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }

    int max_deg = getMaxDegree(N, &adj);
    if(max_deg > N/2){
        cout << "No" << endl;
        return 0;
    }

    vector<int> vomd;
    REP(i,0,N){

        if (static_cast<int>(adj[i].size()) == max_deg) {
        //if(adj[i].size() == max_deg) {
            vomd.push_back(i);
        }
    }

    REP(i,0,static_cast<int>(vomd.size())){
        vector<int> consl;

        int max = 0;
        int max_i = 0;
        for (auto u: adj[vomd[i]]) {
            vector<bool> visited(N, false);
            visited[vomd[i]] = true;
            int num = dfs(u, &visited, &adj);
            if(num > max){
                max=num;
                max_i=u;
            }
            consl.push_back(num);
        }
        sort(consl.begin(), consl.end());
        long long sum = 0;
        REP(j, 0, static_cast<int>(consl.size()-1)){
            sum +=consl[j];
        }
        if(sum+1 == consl[consl.size()-1]){
            // find solution here
            cout << "Yes" << endl;
            vector<bool> visited(N, false);
            visited[vomd[i]] = true;
            dfs(max_i, &visited, &adj);
            visited[vomd[i]] = false;
            REP(k, 0, N){
                if(visited[k]) cout << 'U';
                else cout << 'M';
            }
            cout << endl;
            return 0;
        }

    }
    cout << "No" << endl;



    

    
    
    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: WRONG ANSWER

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

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: WRONG ANSWER

Test 19

Verdict: ACCEPTED

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: ACCEPTED

Test 26

Verdict: ACCEPTED

Test 27

Verdict: ACCEPTED

Test 28

Verdict: ACCEPTED

Test 29

Verdict: ACCEPTED

Test 30

Verdict: ACCEPTED

Test 31

Verdict: WRONG ANSWER

Test 32

Verdict: ACCEPTED

Test 33

Verdict: ACCEPTED

Test 34

Verdict: ACCEPTED

Test 35

Verdict: ACCEPTED

Test 36

Verdict: WRONG ANSWER

Test 37

Verdict: ACCEPTED

Test 38

Verdict: ACCEPTED

Test 39

Verdict: ACCEPTED

Test 40

Verdict: ACCEPTED

Test 41

Verdict: WRONG ANSWER

Test 42

Verdict: ACCEPTED

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: ACCEPTED

Test 53

Verdict: ACCEPTED

Test 54

Verdict: WRONG ANSWER

Test 55

Verdict: WRONG ANSWER

Test 56

Verdict: WRONG ANSWER

Test 57

Verdict: ACCEPTED

Test 58

Verdict: WRONG ANSWER

Test 59

Verdict: TIME LIMIT EXCEEDED

Test 60

Verdict: TIME LIMIT EXCEEDED

Test 61

Verdict: ACCEPTED