快速排序笔记

以下是练习结果，对算法的理解参考：http://blog.csdn.net/morewindows/article/details/6684558

package com.xh.tech.dac;public class Dac {public static void main(String[] args) {//快速排序int[] arr = {32,5,22,88,56,34,76,37,15,75};quickSort(arr,0,arr.length-1);for (int i = 0; i < arr.length; i++) {System.out.println(arr[i]);}}public static void quickSort(int[] arr,int left,int right){if(left<right){int i = firstSort(arr,left,right);//第一次排序完成后接着对 0到(left==right)的位置开始排序quickSort(arr,left,i-1);//(left==right)的位置到最后排序quickSort(arr,i+1,right);}}public static int firstSort(int[] arr,int left,int right){int base = arr[left];while(left<right){//从右向左寻找，如果找到right>left则和left互换位置，left+1while (right>left) {if(base>=arr[right]){arr[left] = arr[right];left++;break;}right--;}//从左向右找，如果找到left<right则和right互换，right-1while (left<right) {if(base<=arr[left]){arr[right] = arr[left];right--;break;}left++;}}//当left ==right时，将基数放入arr[left] = base;return left;}}