题目描述

快速排序

java 代码 参考了其他人怎么写java读入数据的写法

import java.util.Scanner;
import java.io.BufferedInputStream;
import java.util.Arrays;
public class Main{
    public static void main(String[] args){

        Scanner scanner=new Scanner(new BufferedInputStream(System.in));
        int n=scanner.nextInt();
        int[]nums=new int[n];
        for(int i=0;i<n;i++){
            nums[i]=scanner.nextInt();
        }
        quickSort(nums,0,n-1);
        // for(int i=0;i<n;i++){
        //     System.out.print(nums[i]+" ");
        // }
        Arrays.stream(nums).forEach(a->System.out.print(a+" "));

    }

    public  static void quickSort(int []nums,int left,int right){
        if(left>=right){
            return;
        }
        int i=left-1;
        int j=right+1;
        int privot=nums[left];
        while(i<j){
            do i++;while(nums[i]<privot);
            do j--;while(nums[j]>privot);
            if(i<j){
                swap(nums,i,j);
            }
        }
        quickSort(nums,left,j);
        quickSort(nums,j+1,right);
    }

    public static  void swap(int[]nums,int left,int right){
        int t=nums[left];
        nums[left]=nums[right];
        nums[right]=t;
    }
}