LeetCode 1356. 根据数字二进制下 1 的数目排序

题目链接：https://leetcode-cn.com/problems/sort-integers-by-the-number-of-1-bits/

代码：

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/*
给你一个整数数组 arr 。请你将数组中的元素按照其二进制表示中数字 1 的数目升序排序。
 
如果存在多个数字二进制中 1 的数目相同，则必须将它们按照数值大小升序排列。
 
请你返回排序后的数组。
*/
 
#include<iostream>
#include<vector>
#include<algorithm>
#include<set>
 
using namespace std;
 
class NumInfo
{
public:
    int num;
    int num_1;
public:
    NumInfo(int n) :num(n)
    {
        num_1 = get_num_1(num);
    }
 
    bool operator <(const NumInfo& numInfo)const
    {
        if (this->num_1 < numInfo.num_1)
        {
            return true;
        }
        else if(this->num_1 == numInfo.num_1)
        {
            if (this->num < numInfo.num)
            {
                return true;
            }
            else
            {
                return false;
            }
        }
        else
        {
            return false;
        }
    }
 
private:
 
    int get_num_1(int n)
    {
        int count = 0;
 
        while (n)
        {
            ++count;
            n = (n - 1) & n;
        }
 
        return count;
    }
};
 
class Solution {
public:
    vector<int> sortByBits(const vector<int>& arr) 
    {
        if (arr.empty())
        {
            vector<int> result;
            return  result;
        }
         
        vector<NumInfo> numVect;
        for (auto num : arr)
        {
            NumInfo numInfo(num);
            numVect.push_back(numInfo);
        }
 
        sort(numVect.begin(), numVect.end());
 
        vector<int> result;
        for (auto num_info : numVect)
        {
            result.push_back(num_info.num);
        }
 
        return result;
    }
};
 
int main()
{
    vector<int> arr{ 10,100,1000,10000 };
 
    Solution solution;
    vector<int> result = solution.sortByBits(arr);
 
    for (auto num : result)
    {
        cout << num << " ";
    }
 
    return 0;
}