BOJ 2910 - 빈도 정렬 [C++]

문제

링크

풀이

#include <iostream>
#include <utility>
#include <map>
#include <vector>
#include <algorithm>
using namespace std;
 
bool cmp(pair<int, pair<int, int> > &a, pair<int, pair<int, int> > &b) {
  if (a.second.first == b.second.first) return a.second.second < b.second.second;
  return a.second.first > b.second.first;
}
 
void solve(void) {
  int n, c; cin >> n >> c;
 
  map<int, pair<int, int> > mp;
  for (int i=0; i<n; i++) {
    int x; cin >> x;
    if (mp.find(x) == mp.end()) mp[x] = make_pair(1, i);
    else mp[x].first++;
  }
 
  vector<pair<int, pair<int, int> > > v;
  for (auto it=mp.begin(); it!=mp.end(); it++) {
    v.push_back(make_pair(it->first, make_pair(it->second.first, it->second.second)));
  }
  sort(v.begin(), v.end(), cmp);
 
  for (int i=0; i<v.size(); i++) {
    for (int j=0; j<v[i].second.first; j++) cout << v[i].first << " ";
  }
}
 
int main(void) {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
 
  solve();
  return 0;
}