最小的k个数

题目描述
输入n个整数，找出其中最小的K个数。例如输入4,5,1,6,2,7,3,8这8个数字，则最小的4个数字是1,2,3,4,。

import java.util.ArrayList;

public class Solution {
    
    public ArrayList<Integer> GetLeastNumbers_Solution(int[] input, int k) {
        
        ArrayList<Integer> array = new ArrayList<Integer>();
        if(k > input.length){
            
            return array;
        }
        qSort(input, 0, input.length - 1);
        for(int i = 0; i < k; i++){
            
            array.add(input[i]);
        }
        return array;
    }
    public void qSort(int[] a, int left, int right) {
        
        if(left >= right) {
            
            return;
        }
        int val = a[left];
        int i = left;
        int j = right;
        while(i < j) {
            
            while(j > i){
                
                if(a[j] < val)
                    break;
                else
                    j--;
            }
            while(i < j) {
                
                if(a[i] > val)
                    break;
                else
                    i ++;
            }
            int temp = a[i];
            a[i] = a[j];
            a[j] = temp;
        }
        a[left] = a[i];
        a[i] = val;
        qSort(a, left, i - 1);
        qSort(a, i + 1, right);
    }
    public static void main(String[] args) {
        
        Solution obj = new Solution();
        int [] array = {1,3,2,5,6,5};
        obj.qSort(array, 0, array.length - 1);
        for(int i : array){
            
            System.out.println(i);
        }
    }
}