sort

1. quickSort

import random
class Solution:
    def partition(self,nums,left,right):
        idx=random.randint(left,right)      # 闭区间
        pivot=nums[idx]

        nums[idx],nums[right]=nums[right],nums[idx]
        
        pos=left
        for i in range(left,right):
            if(nums[i]<pivot):
                nums[i],nums[pos]=nums[pos],nums[i]
                pos+=1
        
        nums[pos],nums[right]=nums[right],nums[pos]
        return pos

    def quickSort(self,nums):
        if(len(nums)==1):
            return nums
        left,right=0,len(nums)-1

        return self.quickSort_helper(nums,left,right)

    def quickSort_helper(self,nums,left,right):
        if(left<right):
            pos=self.partition(nums,left,right)
            self.quickSort_helper(nums,left,pos-1)
            self.quickSort_helper(nums,pos+1,right)
        
        return nums


nums=[5,2,34,21]
print(Solution().quickSort(nums))

2. mergeSort

class Solution2:
    def merge(self,nums,left,mid,right):
        helper=[]
        i=left
        j=mid+1
        while i<=mid and j<=right:
            if(nums[i]<nums[j]):
                helper.append(nums[i])
                i+=1
            else:
                helper.append(nums[j])
                j+=1
        
        while i<=mid:
            helper.append(nums[i])
            i+=1
        
        while j<=right:
            helper.append(nums[j])
            j+=1
        
        for k in range(len(helper)):
            nums[k+left]=helper[k]


    def mergeSort(self,nums):
        left,right=0,len(nums)-1
        return self.mergeSort_helper(nums,left,right)
    
    def mergeSort_helper(self,nums,left,right):
        if(left<right):
            mid=left+((right-left)>>1)
            self.mergeSort_helper(nums,left,mid)
            self.mergeSort_helper(nums,mid+1,right)
            self.merge(nums,left,mid,right)

        return nums