114 lines
3.4 KiB
Python
114 lines
3.4 KiB
Python
|
"""
|
||
|
|
排序 - 冒泡排序(简单O(N**2)) / 归并排序(高级O(N*log2N))
|
||
|
|
冒泡排序
|
||
|
|
34, 99, 52, 11, 47, 68, 50, 84
|
||
|
|
34, 52, 11, 47, 68, 50, 84, 99
|
||
|
|
34, 11, 47, 52, 50, 68, 84
|
||
|
|
11, 34, 47, 50, 52, 68
|
||
|
|
|
||
|
|
快速排序
|
||
|
|
34, 99, 52, 11, 47, 68, 50, 84
|
||
|
|
{34, 11, 47}, {50}, {99, 52, 68, 84}
|
||
|
|
{11}, {34}, {47}, {50}, {52, 68, 84}, {99}
|
||
|
|
{11}, {34}, {47}, {50}, {52}, {68, 84}, {99}
|
||
|
|
{11}, {34}, {47}, {50}, {52}, {68}, {84}, {99}
|
||
|
|
|
||
|
|
归并排序 - 分治法(divide-and-conquer)
|
||
|
|
34, 99, 52, 11, 47, 68, 50, 84
|
||
|
|
{34, 99, 52, 11}, {47, 68, 50, 84}
|
||
|
|
{34, 99}, {52, 11}, {47, 68}, {50, 84}
|
||
|
|
{34}, {99}, {52}, {11}, {47}, {68}, {50}, {84}
|
||
|
|
{34, 99}, {11, 52}, {47, 68}, {50, 84}
|
||
|
|
{11, 34, 52, 99}, {47, 50, 68, 84}
|
||
|
|
{11, 34, 47, 50, 52, 68, 84, 99}
|
||
|
|
|
||
|
|
在使用分治法的时候通常都会使用到递归调用这种编程手段
|
||
|
|
一个函数直接或间接的调用了自身就称之为递归调用
|
||
|
|
"""
|
||
|
|
|
||
|
|
|
||
|
|
# 9 1 2 3 4 5 6 7 8
|
||
|
|
# 2 3 4 5 6 7 8 9 1
|
||
|
|
# *前面的参数称为位置参数, *后面的参数称为命名关键字参数
|
||
|
|
# 所谓命名关键字参数就是调用函数时必须以"参数名=参数值"的形式传入参数
|
||
|
|
def bubble_sort(origin_items, *, comp=lambda x, y: x > y):
|
||
|
|
"""冒泡排序"""
|
||
|
|
items = origin_items[:]
|
||
|
|
length = len(items)
|
||
|
|
for i in range(1, length):
|
||
|
|
swapped = False
|
||
|
|
for j in range(0, length - i):
|
||
|
|
if comp(items[j], items[j + 1]):
|
||
|
|
items[j], items[j + 1] = items[j + 1], items[j]
|
||
|
|
swapped = True
|
||
|
|
if swapped:
|
||
|
|
swapped = False
|
||
|
|
for j in range(length - i - 1, i - 1, -1):
|
||
|
|
if comp(items[j - 1], items[j]):
|
||
|
|
items[j - 1], items[j] = items[j], items[j - 1]
|
||
|
|
swapped = True
|
||
|
|
if not swapped:
|
||
|
|
break
|
||
|
|
return items
|
||
|
|
|
||
|
|
|
||
|
|
def merge(list1, list2, comp=lambda x, y: x <= y):
|
||
|
|
""""有序合并(将两个有序的列表合并成一个新的有序的列表)"""
|
||
|
|
list3 = []
|
||
|
|
index1, index2 = 0, 0
|
||
|
|
while index1 < len(list1) and index2 < len(list2):
|
||
|
|
if comp(list1[index1], list2[index2]):
|
||
|
|
list3.append(list1[index1])
|
||
|
|
index1 += 1
|
||
|
|
else:
|
||
|
|
list3.append(list2[index2])
|
||
|
|
index2 += 1
|
||
|
|
list3 += list1[index1:]
|
||
|
|
list3 += list2[index2:]
|
||
|
|
return list3
|
||
|
|
|
||
|
|
|
||
|
|
def merge_sort(origin_items, comp=lambda x, y: x <= y):
|
||
|
|
"""归并排序"""
|
||
|
|
if len(origin_items) <= 1:
|
||
|
|
return origin_items[:]
|
||
|
|
mid = len(origin_items) // 2
|
||
|
|
left = merge_sort(origin_items[:mid], comp)
|
||
|
|
right = merge_sort(origin_items[mid:], comp)
|
||
|
|
return merge(left, right, comp)
|
||
|
|
|
||
|
|
|
||
|
|
class Person:
|
||
|
|
"""人"""
|
||
|
|
|
||
|
|
def __init__(self, name, age):
|
||
|
|
self.name = name
|
||
|
|
self.age = age
|
||
|
|
|
||
|
|
def __repr__(self):
|
||
|
|
return f'{self.name}: {self.age}'
|
||
|
|
|
||
|
|
|
||
|
|
def main():
|
||
|
|
# list1 = [12, 35, 48, 87, 92]
|
||
|
|
# list2 = [39, 44, 50, 60, 77, 88]
|
||
|
|
# list3 = merge(list1, list2)
|
||
|
|
# print(list3)
|
||
|
|
items = [34, 99, 52, 11, 47, 50, 84]
|
||
|
|
print(items)
|
||
|
|
print(merge_sort(items))
|
||
|
|
# items = ['hi', 'hello', 'orange', 'watermelon', 'zoo', 'pitaya']
|
||
|
|
# items = [
|
||
|
|
# Person("LuoHao", 38), Person("Baiyuanfang", 25),
|
||
|
|
# Person("Zhangsanfeng", 120), Person("Lee", 18)
|
||
|
|
# ]
|
||
|
|
# new_items = bubble_sort(items, comp=lambda x, y: len(x) > len(y))
|
||
|
|
# new_items = bubble_sort(items, comp=lambda x, y: x.age > y.age)
|
||
|
|
# print(items)
|
||
|
|
# print(new_items)
|
||
|
|
|
||
|
|
|
||
|
|
if __name__ == '__main__':
|
||
|
|
main()
|
||
|
|
|