快速排序的两种思路，java和python实现

java版的就是传统的用low和high两个指针去写

package smile;

import java.util.Arrays;

public class quickSort {
       public static void main(String args[]) {
           int[] num = {10,2,12,3,5,1,7,8,9,20};
//         sort(num,0,10);
           int len = num.length;
           quick(num,0,len-1);
           System.out.println(Arrays.toString(num));
       }
//       public static void sort(int[] nums,int begin,int end) {
//         int key = nums[begin];
//         int count=0;
//         int temp;
//         for(int i=begin;i<end;i++) {
//             if(nums[i]<=key) {
//                 temp = nums[i];
//                 nums[i] =nums[count];
//                 nums[count]  = temp;
//                 count++;
//             }
//         }
//         for(int i=0;i<count;i++) {
//             System.out.println(nums[i]);
//         }
//         System.out.println("满足条件的个数:"+count);
//         System.out.println("不满足条件的个数:"+(nums.length-count));
//       }
       
       
//       快排
//       分区函数
       public static int divPart(int[] nums,int low,int high) {
           int flag = nums[low];
           while(low<high) {
               while(low<high&&nums[high]>=flag) {                              
                    --high;
               }                   
               nums[low] = nums[high];                                  
               while(low<high&&nums[low]<=flag) {                           
                    ++low;
               }              
               nums[high] = nums[low];                                                              
           }
           nums[low] = flag;  
           return low;
       }
       
//       递归排序
       public static void quick(int []num,int low,int high) {
           if(low<high) {
               int middle = divPart(num,low,high);
               quick(num,low,middle);
               quick(num,middle+1,high);
           }
       }
       
}

python不用low，high指针

# 不用low以及high指针进行快排
# 分区函数
def divison(list,start,end):
    # 初始化
    count=1
    key=list[start]
    # 将满足条件的元素放在列表前边
    for i in range(start+1,end+1):
        if list[i]<=key:
            temp = list[i]
            list[i] = list[start+count]
            list[start+count] = temp
            count+=1
    # 将元素前移一位
    for i in range(0,count-1):
        list[start+i] = list[start+i+1]
    # 将key（基准元素）值放在空位上
    list[start+count-1] = key
    # 返回基准元素下标
    return start+count-1

# 递归调用快排算法
def quick_sort1(list,start,end):
    if start<end:
        index = divison(list,start,end)
        quick_sort1(list,0,index-1)
        quick_sort1(list,index+1,end)
# 封装
def quick_sort(list):
    quick_sort1(list,0,len(list)-1)

if __name__ == '__main__':
    list = [1,5,23,-1,6,9,2,3]
    quick_sort(list)
    print(list)