def selection_sort(lists):
length = len(lists)
for i in range(length):
min_index = i
for j in range(i + 1, length):
if lists[min_index] > lists[j]:
min_index = j
swap(lists, min_index, i)
return lists
def bubble_sort(lists):
length = len(lists)
for i in range(length):
for j in range(
0,
length - i - 1,
):
if lists[j] > lists[j + 1]:
swap(lists, j, j + 1)
return lists
def sort(cls, lists, *args):
if len(args):
left = args[0]
right = args[1]
if left >= right:
return
swap(lists, left, int(random.random() * (right - left + 1)) + left)
base = lists[left]
"""
lists[left+1...lt] < v
lists[gt...right] > v
lists[lt+1...i) == v
保证初始化的三个区间全部为空
后续相应元素逐个添加进去
"""
lt = left
gt = right + 1
i = left + 1
while i < gt:
if lists[i] < base:
swap(lists, lt + 1, i)
lt += 1
i += 1
elif lists[i] > base:
swap(lists, gt - 1, i)
gt -= 1
else:
i += 1
swap(lists, left, lt)
cls.sort(lists, left, lt - 1)
cls.sort(lists, gt, right)
else:
cls.sort(lists, 0, len(lists) - 1)
def partition(lists, left, right):
"""
选取第一个元素为标定点
lists[left+1...k] < base; lists[k+1...right] > base
:param lists:
:param left:
:param right:
:return:
"""
base = lists[left]
k = left
for i in range(left + 1, right + 1):
if base > lists[i]:
k += 1
swap(lists, k, i)
swap(lists, left, k)
return k
def insertion_sort(lists, *args):
if len(args):
for i in range(args[0] + 1, args[1] + 1):
for j in range(i, 0, -1):
if lists[j] < lists[j - 1]:
swap(lists, j, j - 1)
else:
break
else:
length = len(lists)
for i in range(1, length):
for j in range(i, 0, -1):
if lists[j] < lists[j - 1]:
swap(lists, j, j - 1)
else:
break
return lists
def partition(lists, left, right):
# 随机标定点
# lists[left...l] < base; lists[r...right] >= base
swap(lists, left, int(random.random() * (right - left + 1)) + left)
base = lists[left]
l = left + 1
r = right
while True:
while l <= right and lists[l] < base:
l += 1
while r >= left + 1 and lists[r] > base:
r -= 1
if l > r:
break
swap(lists, l, r)
l += 1
r -= 1
"""
一次完整的遍历之后，l会停留在第一个大于base的位置，r会停留在第一个小于base的位置
故将base的值与lists[r]进行交换，完成一次partition
"""
swap(lists, left, r)
return r
def partition(lists, left, right):
"""
对于普通快排，若排序数组为近乎有序的
每次选取第一个元素为标定点则会将算法时间复杂度往O（n*2）提高，接近于最坏的处理情况
这种处理场景，随机快排能大幅度降低时间复杂度
lists[left+1...k] < base; lists[k+1...right] > base
"""
swap(lists, left, int(random.random() * (right - left + 1)) + left)
base = lists[left]
k = left
for i in range(left + 1, right + 1):
if base > lists[i]:
k += 1
swap(lists, k, i)
swap(lists, left, k)
return k