排序[二] 快速排序之JAVA实现

package quickSort;

import Utils.ArrayUtils;

public class QuickSort {
	public static int getIndex(int[] srcArr,int left,int right) {
		int key = srcArr[left];
		while(left<right){
			while(srcArr[right]>key&&left<right)
				right--;
			srcArr[left]=srcArr[right];
			while(srcArr[left]<key&&left<right)
				left++;			
			srcArr[right]=srcArr[left];
		}
		srcArr[left]=key;
		return left;		
	}
	//递归,找出口
	public static void quickSort(int[] arr,int left,int right){
		if(left>=right) {
			return;
		}	
		else {
			int point = getIndex(arr, left, right);
			quickSort(arr, left, point-1);
			quickSort(arr, point+1, right);
		}
	}
	
	public static void main(String[] args) {
		int[] srcArr = ArrayUtils.getArray(6);
		for(int n:srcArr)
			System.out.print(n+"  ");
		System.out.println();
		quickSort(srcArr, 0, srcArr.length-1);
		for(int n:srcArr)
			System.out.print(n+"  ");
	}
}

 

 

工具类:产生随机数.

package Utils;

import java.util.Random;

public class ArrayUtils {
	public static int[] getArray(int len) {
		Random random = new Random();
		int[] a=new int[len];
		for(int i=0;i<len;i++) {
			a[i]=random.nextInt(100);
		}
		return a;
	}
	public static void printArray(int[] arr){
		for(int a:arr)
			System.out.print(a+" ");
		System.out.println();
	}
}

 

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