2019.9.24-快速排序实现（完整代码）

# coding:utf-8

def quick_sort(alist, first, last):
"""快速排序"""
if first >= last:
return
mid_value = alist[first]
low = first
high = last
while low < high:
# high 左移
while low < high and alist[high] >= mid_value:
high -= 1
alist[low] = alist[high]

while low < high and alist[low] < mid_value:
low += 1
alist[high] = alist[low]
#從循環退出時， low==high
alist[low] = mid_value

# 對low左邊的列表執行快速排序
quick_sort(alist, first, low-1)

# 對low右邊的列表排序
quick_sort(alist, low+1, last)

if __name__ == "__main__":
li = [54, 26, 93, 17, 77, 31, 44, 55, 20]
print(li)
quick_sort(li, 0, len(li)-1)
print(li)

 

 

 

 

 

 

 

执行结果