leetcode1636

注意map的按键和按值排序，按值排序需要转为vector

#include<iostream>
#include<map>
#include<vector>
#include<algorithm>
using namespace std;
int cmp(const pair<int,int>c1,const pair<int,int>c2){
    if (c1.second < c2.second)return true;
    if (c1.second > c2.second)return false;
    return c1.first > c2.first;
}
vector<int> frequencySort(vector<int>& nums) {
    map<int, int>mp;
    int n = nums.size();
    for (int i = 0; i < n; i++) {
        mp[nums[i]]++;
    }
    vector<pair<int,int>>v(mp.begin(), mp.end());
    vector<int>v2;
    sort(v.begin(),v.end(), cmp);
    for (int i = 0; i < v.size(); i++) {
        for (int j = 0; j < v[i].second; j++) {
            v2.push_back(v[i].first);
        }
    }
    return v2;
}
int main() {
    vector<int>v;
    int n;
    while (cin >> n) {
        v.push_back(n);
    }
    frequencySort(v);
}