def partition(mylist, start, end):# 若选其他元素作为pivot，下面的while内容需要相应更改pivot = mylist[end]left = startright = endwhile left < right:while left < right and mylist[left] <= pivot:left += 1while left < right and mylist[right] >= pivot:right -= 1if left != right:mylist[left], mylist[right] = mylist[right], mylist[left]mylist[end], mylist[left] = mylist[left], pivotreturn leftdef quick_sort(mylist, start, end):"""mylist: 待排序的 liststart: mylist第一个元素索引end: mylist最后一个元素索引"""if start < end:mid = partition(mylist, start, end)quick_sort(mylist, start, mid - 1)quick_sort(mylist, mid + 1, end)if __name__ == "__main__":mylist = [12, 33, 199, 0, 54, 77, 11, 54, 9, 7]quick_sort(mylist, 0, len(mylist) - 1)print(f'快速排序后：{mylist}')

class Stack():"""简单实现一个栈，本质就是个list"""def __init__(self):self.items = []def is_empty(self):return self.items == []def push(self, item):self.items.append(item)def pop(self):return self.items.pop()# 此方法与上面例子一样，保持不变
def partition(mylist, start, end):# 若选其他元素作为pivot，下面的while内容需要相应更改pivot = mylist[end]left = startright = endwhile left < right:while left < right and mylist[left] <= pivot:left += 1while left < right and mylist[right] >= pivot:right -= 1if left != right:mylist[left], mylist[right] = mylist[right], mylist[left]mylist[end], mylist[left] = mylist[left], pivotreturn leftdef quick_sort(mylist):stack = Stack()start = 0end = len(mylist) - 1if start < end:stack.push((start, end))while not stack.is_empty():start, end = stack.pop()mid = partition(mylist, start, end)if start < mid - 1:stack.push((start, mid - 1))if mid + 1 < end:stack.push((mid + 1, end))