[백준] 온라인 저지 7785번 : 회사에 있는 사람(C++), 해시

https://www.acmicpc.net/problem/7785

#include <iostream>
#include <unordered_map>
#include <algorithm>

using namespace std;

int main()
{
	int N;
	cin >> N;
	string name, status;

	unordered_map<string, string> logs;

	for (int i = 0; i < N; ++i)
	{
		cin >> name >> status;
		
		if (status == "leave")
			logs.erase(name);
		else logs.insert({ name, status });
	}
	
	vector<string> names;

	for (const auto& log : logs)
		names.push_back(log.first);

	sort(names.begin(), names.end(), greater<>());

	for (const string& name : names)
		cout << name << "\n";

	return 0;
}