算法之 快速排序

L = [5, 2, 0, 7, 3, 8, 9, 4, 2, 1]


def quick_sort(L, low, hight):
    i = low
    j = hight
    if i >= j:
        return L

    key = L[low]
    while i<j: # 本L的左右拆分整理
        while i<j and key <=L[j]:
            j-=1
        L[i] = L[j]
        # i=i+1 # 错误, 因为 i=j的时候,while 不循环,但是 i=i+1产生了副作用

        while i<j and key >= L[i]:
            i+=1
        L[j] = L[i]
        # j = j-1

    L[i] = key
    quick_sort(L, low, i-1) # left sort
    quick_sort(L, j+1, hight) # right sort
    return L
 
quick_sort(L, 0, len(L)-1)