1、冒泡排序
def bubble_sort(alist):
"""冒泡排序"""
n = len(alist)
for j in range(0,n-1):
count = 0
for i in range(0,n-1-j):
# 从头走到尾
if alist[i] > alist[i+1]:
count += 1
alist[i],alist[i+1] = alist[i+1],alist[i]
print(j,i)
if 0 == count:
break
return alist
if __name__ == '__main__':
a = [1,5,3,6,823,242,6,2,4,5,6]
ret = bubble_sort(a)
print(ret)
li = [54, 26, 93, 17, 77, 31, 44, 55, 20]
bubble_sort(li)
print(li)
li = [1,2,3,4,5]
bubble_sort(li)
print(li)
2、选择排序
def select_sort(alist):
"""选择排序"""
n = len(alist)
for j in range(0,n-1):
min_index = j
for i in range(j+1,n):
# 从j+1走到尾
if alist[i] < alist[min_index]:
min_index = i
alist[j],alist[min_index] = alist[min_index],alist[j]
print(alist)
if __name__ == '__main__':
a = [1,5,3,6,823,242,6,2,4,5,6]
select_sort(a)
# print(a)
li = [54, 26, 93, 17, 77, 31, 44, 55, 20]
select_sort(li)
print(li)
3、插入排序
def insert_sort(alist):
"""插入排序"""
n = len(alist)
# 从右边的无序序列中取出多少个元素执行这样的过程
for j in range(1,n):
# j = [1,2,3,...n-1]
# i 代表内层循环起始
i = j
# 执行从右边的无序序列中取出第一个元素，即i位置的元素，然后将其插入前面的正确位置中
while i> 0:
if alist[i] < alist[i-1]:
alist[i-1],alist[i] = alist[i],alist[i-1]
i -= 1
else:
break
print(alist)
if __name__ == '__main__':
a = [1,5,3,6,823,242,6,2,4,5,6]
insert_sort(a)
# print(a)
li = [54, 26, 93, 17, 77, 31, 44, 55, 20]
insert_sort(li)
print(li)
4、希尔排序
def shell_sort(alist):
"""希尔排序"""
n = len(alist)
# n =9
gap = n//2
# gap变化到0之前，插入算法执行的次数
while gap >=1:
# 插入算法， 与普通的插入算法的区别就是gap步长
for j in range(gap,n):
# j = [gap, gap+1, gap+2, ..., n-1]
i = j
while i >0:
if alist[i] < alist[i-gap]:
alist[i], alist[i-gap] = alist[i-gap], alist[i]
i -= gap
else:
break
# 缩短gap步长
gap //= 2
if __name__ == '__main__':
a = [1,5,3,6,823,242,6,2,4,5,6]
shell_sort(a)
print(a)
li = [54, 26, 93, 17, 77, 31, 44, 55, 20]
shell_sort(li)
print(li)
5、快速排序
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游标左移
while low < high and alist[high] >= mid_value:
high -= 1
alist[low] = alist[high]
# low游标右移
while low < high and alist[low] < mid_value:
low += 1
alist[high] = alist[low]
# 从循环退出时，low==high
alist[low] = mid_value
# 对low左边的列表执行快速排序
quick_sort(alist, first, low-1)
# 对low右边的列表执行快速排序
quick_sort(alist, low+1, last)
if __name__ == '__main__':
a = [1,5,3,6,823,242,6,2,4,5,6]
quick_sort(a,0,len(a)-1)
print(a)
li = [54, 26, 93, 17, 77, 31, 44, 55, 20]
quick_sort(li,0,len(li)-1)
print(li)
6、归并排序
def merge_sort(alist):
"""归并排序"""
n = len(alist)
if n <= 1:
return alist
mid = n//2
# left_li 采用归并排序后形成的有序的新的列表
left_li =merge_sort(alist[:mid])
print("left_li :", left_li)
# right_li 采用归并排序后形成的有序的新的列表
right_li = merge_sort(alist[mid:])
print("right_li:",right_li)
#将两个有序的子序列合并为一个新的整体
# merge(left,right)
left_pointer , right_pointer = 0,0
result = []
while left_pointer < len(left_li) and right_pointer < len(right_li):
if left_li[left_pointer] < right_li[right_pointer]:
result.append(left_li[left_pointer])
left_pointer += 1
else:
result.append(right_li[right_pointer])
right_pointer += 1
result += left_li[left_pointer:]
result += right_li[right_pointer:]
print("result :", result)
print("*"*50)
return result
if __name__ == '__main__':
a = [1,5,3,6,823,242,6,2,4,5,6]
ret = merge_sort(a)
print(ret)
li = [54, 26, 93, 17, 77, 31, 44, 55, 20]
ret = merge_sort(li)
print(ret)
7、侏儒排序
def gnomesort(seq):
'''侏儒排序'''
i = 0
while i < len(seq):
if i == 0 or seq[i-1] <= seq[i]:
print("+:",i)
i += 1
else:
print("修改:",i)
seq[i], seq[i-1] = seq[i-1], seq[i]
print(a)
i -= 1
if __name__ == '__main__':
a = [1,5,3,6,823,242,6,2,4,5,6]
gnomesort(a)
print(a)
li = [54, 26, 93, 17, 77, 31, 44, 55, 20]
gnomesort(li)
print(li)
li = [1,2,3,4,5]
gnomesort(li)
print(li)
