[C++] [Map] 프로그래머스 해시 : 베스트앨범

https://programmers.co.kr/learn/courses/30/lessons/42579

코딩테스트 연습 - 베스트앨범 | 프로그래머스

#include <string>
#include <vector>
#include <map>
#include <utility>
#include <iostream>
#include <algorithm>
#include <functional>

using namespace std;
bool cmpM(const pair<int, string> &a, const pair<int, string> &b) {
	return a.first > b.first;
}

bool cmpV(const pair<int, int> &a, const pair<int, int> &b) {
	return a.first > b.first;
}
vector<pair<int, string>> mSort(map<string, int> &M) {
	vector<pair<int, string>> V;

	for (auto i : M)
		V.push_back(make_pair(i.second, i.first));

	sort(V.begin(), V.end(), greater<int>());

	return V;
}

int main(void) {
	vector<string> genres;
	vector<int> plays;
	map<string, int> M;
	multimap<string, pair<int, int>> MM;

	for (int i = 0; i < 5; i++) {
		string str;
		int x;
		cin >> str >> x;
		genres.push_back(str);
		plays.push_back(x);
	}

	for (int i = 0; i < genres.size(); i++) {
		M[genres[i]] += plays[i];
		MM.insert(make_pair(genres[i], make_pair(plays[i], i)));
	}

	vector<pair<int, string>> V = mSort(M);

	multimap<string, pair<int, int>>::iterator iter;
	pair<multimap<string, pair<int, int>>::iterator, multimap<string, pair<int, int>>::iterator> iter_pair;


	for (auto i : V) {
		vector<pair<int, int>> lastV;

		iter_pair = MM.equal_range(i.second);
		for (iter = iter_pair.first; iter != iter_pair.second; ++iter) {
			lastV.push_back(make_pair(iter->second.first, iter->second.second));
			//cout<<iter->first<<' '<<iter->second.first<<' '<<iter->second.second<<endl;
		}
		if (iter_pair.second - iter_pair.first < 2) {
			answer.push_back(lastV[0].second);
		}
		else {
			sort(lastV.begin(), lastV.end(), cmpV);

			for (int i = 0; i<2; i++)
				answer.push_back(lastV[i].second);
		}
	}

	return 0;
}