python---归并排序
作者：互联网
小的列表排序，归并性能一般呀。
# coding = utf-8
# ========归并排序========
def merge_sort(a_list):
loop_count = 0
print('Splitting ', a_list)
if len(a_list) > 1:
loop_count += 1
mid = len(a_list) // 2
left_half = a_list[:mid]
right_half = a_list[mid:]
merge_sort(left_half)
merge_sort(right_half)
i = 0
j = 0
k = 0
while i < len(left_half) and j < len(right_half):
loop_count += 1
if left_half[i] < right_half[j]:
a_list[k] = left_half[i]
i += 1
else:
a_list[k] = right_half[j]
j += 1
k += 1
while i < len(left_half):
loop_count += 1
a_list[k] = left_half[i]
i += 1
k += 1
while j < len(right_half):
loop_count += 1
a_list[k] = right_half[j]
j += 1
k += 1
print('Merging ', a_list)
print('======== shell_sort loop_count========', loop_count)
my_list = [4, 5, 7, 2, 9, 7, 9, 54, 765, 45, 9876, 34, 12343, 36]
merge_sort(my_list)
print(my_list)
D:\cheng\test\Scripts\python.exe D:/GIT/Prism4K/Prism4K/document/tests.py Splitting [4, 5, 7, 2, 9, 7, 9, 54, 765, 45, 9876, 34, 12343, 36] Splitting [4, 5, 7, 2, 9, 7, 9] Splitting [4, 5, 7] Splitting [4] Merging [4] ======== shell_sort loop_count======== 0 Splitting [5, 7] Splitting [5] Merging [5] ======== shell_sort loop_count======== 0 Splitting [7] Merging [7] ======== shell_sort loop_count======== 0 Merging [5, 7] ======== shell_sort loop_count======== 3 Merging [4, 5, 7] ======== shell_sort loop_count======== 4 Splitting [2, 9, 7, 9] Splitting [2, 9] Splitting [2] Merging [2] ======== shell_sort loop_count======== 0 Splitting [9] Merging [9] ======== shell_sort loop_count======== 0 Merging [2, 9] ======== shell_sort loop_count======== 3 Splitting [7, 9] Splitting [7] Merging [7] ======== shell_sort loop_count======== 0 Splitting [9] Merging [9] ======== shell_sort loop_count======== 0 Merging [7, 9] ======== shell_sort loop_count======== 3 Merging [2, 7, 9, 9] ======== shell_sort loop_count======== 5 Merging [2, 4, 5, 7, 7, 9, 9] ======== shell_sort loop_count======== 8 Splitting [54, 765, 45, 9876, 34, 12343, 36] Splitting [54, 765, 45] Splitting [54] Merging [54] ======== shell_sort loop_count======== 0 Splitting [765, 45] Splitting [765] Merging [765] ======== shell_sort loop_count======== 0 Splitting [45] Merging [45] ======== shell_sort loop_count======== 0 Merging [45, 765] ======== shell_sort loop_count======== 3 Merging [45, 54, 765] ======== shell_sort loop_count======== 4 Splitting [9876, 34, 12343, 36] Splitting [9876, 34] Splitting [9876] Merging [9876] ======== shell_sort loop_count======== 0 Splitting [34] Merging [34] ======== shell_sort loop_count======== 0 Merging [34, 9876] ======== shell_sort loop_count======== 3 Splitting [12343, 36] Splitting [12343] Merging [12343] ======== shell_sort loop_count======== 0 Splitting [36] Merging [36] ======== shell_sort loop_count======== 0 Merging [36, 12343] ======== shell_sort loop_count======== 3 Merging [34, 36, 9876, 12343] ======== shell_sort loop_count======== 5 Merging [34, 36, 45, 54, 765, 9876, 12343] ======== shell_sort loop_count======== 8 Merging [2, 4, 5, 7, 7, 9, 9, 34, 36, 45, 54, 765, 9876, 12343] ======== shell_sort loop_count======== 15 [2, 4, 5, 7, 7, 9, 9, 34, 36, 45, 54, 765, 9876, 12343] Process finished with exit code 0
标签：count,sort,归并,shell,python,Splitting,Merging,排序,loop 来源： https://www.cnblogs.com/aguncn/p/10689506.html