一、题目描述

二、算法原理

三、代码实现

class Solution {
public:
    int getrandom(int left,int right,vector<int>& stock)
    {
        return stock[rand()%(right-left+1)+left];
    }

    void qsort(int l,int r,vector<int>& stock,int cnt)
    {
        if(l>=r)
        {
            return;
        }
        int key=getrandom(l,r,stock);
        int i=l,left=l-1,right=r+1;

        while(i<right)
        {
            if(stock[i]<key) swap(stock[++left],stock[i++]);
            else if(stock[i]==key) i++;
            else swap(stock[i],stock[--right]);
        }

        int a=left-l+1,b=right-left-1,c=r-right+1;
        if(a>cnt)
        {
            qsort(l,left,stock,cnt);
        }
        else if(a+b>=cnt)
        {

        }
        else
        {
            qsort(right,r,stock,cnt-a-b);
        }
    }

    vector<int> inventoryManagement(vector<int>& stock, int cnt) 
    {
        srand(time(NULL));
        qsort(0,stock.size()-1,stock,cnt);
        return {stock.begin(),stock.begin()+cnt};
    }
};