BOJ 1764 듣보잡

1 개요

BOJ 1764 듣보잡

• 백준 온라인 저지 1764번 문제
• BOJ 14단계

2 C++

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

int N, M, i, cnt;
string name;
map<string, int> m;
map<string, int>::iterator j;
list<string> lst;

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    
    cin >> N >> M;
    cnt = 0;
    for(i=0; i<N+M; i++) {
        cin >> name;
        if (m.find(name) == m.end()) {
            m[name] = 1;
            continue;
        }
        m[name]++;
        if(m[name] == 2) cnt++;
    }
    for(j=m.begin(); j!=m.end(); j++) {
        if(j->second==2) lst.push_back(j->first);
    }
    cout << lst.size() << "\n";
    for (auto const& el: lst) {
        cout << el << "\n";        
    }
}