首先排序分为四种:
交换排序: 包括冒泡排序,快速排序。
选择排序: 包括直接选择排序,堆排序。
插入排序: 包括直接插入排序,希尔排序。
合并排序: 合并排序。
冒泡排序
def bubble_sort(lists):
#冒泡排序
count = len(lists)
for i in range(0, count):
for j in range(i + 1, count):
if lists[i] > lists[j]:
lists[i], lists[j] = lists[j], lists[i]
return lists
快速排序
def quick_sort(lists, left, right):
#快速排序
if left >= right:
return lists
key = lists[left]
low = left
high = right
while left < right:
while left < right and lists[right] >= key:
right -= 1
lists[left] = lists[right]
while left < right and lists[left] <= key:
left += 1
lists[right] = lists[left]
lists[right] = key
quick_sort(lists, low, left-1)
quick_sort(lists, left+1, high)
return lists
直接选择排序
def select_sort(lists):
#选择排序
count = len(lists)
for i in range(0, count):
min = i
for j in range(i+1, count):
if lists[min] > lists[j]:
min = j
lists[min], lists[i] = lists[i], lists[min]
return lists
堆排序
那么要实现堆排序,必须要做两件事情:
第一:构建大根堆。
第二:输出大根堆。
def adjust_heap(lists, i, size):
lchild = 2 * i + 1
rchild = 2 * i + 2
max = i
if i < size / 2:
if lchild < size and lists[lchild] > lists[max]:
max = lchild
if rchild < size and lists[rchild] > lists[max]:
max = rchild
if max != i:
lists[max], lists[i] = lists[i], lists[max]
adjust_heap(lists, max, size)
def build_heap(lists, size):
for i in range(0, (size/2))[::-1]:
adjust_heap(lists, i, size)
def heap_sort(lists):
size = len(lists)
build_heap(lists, size)
for i in range(0, size)[::-1]: #采用倒序的方式
lists[0], list[i] = lists[i], lists[0]
adjust_heap(lists, 0, i)
直接插入排序
def insert_sort(lists):
#插入排序
count = len(lists)
for i in range(1, count):
key = lists[i]
j = i -1
while j >= 0:
if lists[j] > key:
lists[j + 1] = lists[j]
lists[j] = key
j -= 1
return lists
希尔排序
def shell_sort(lists):
#希尔排序
count = len(lists)
step = 2
group = count / step
while group > 0:
for i in range(0, group):
j = i + group
while j < count:
k = j - group
key = lists[i]
while k >= 0:
if lists[k] > key:
lists[k + group] = lists[k]
lists[k] = key
k -= group
j += group
group /= step
return lists
归并排序
#归并排序
def merge(left, right):
i, j = 0, 0
result = []
while i < len(left) and j < len(right):
if left[i] <= right[j]:
result.append(left[i])
i += 1
else:
result.append(right[j])
j += 1
result += left[i:]
result += right[j:]
return result
def merge_sort(lists):
#归并排序
if len(lists) <= 1:
return lists
num = len(lists) / 2
left = merge_sort(lists[:num])
right = merge_sort(lists[num:])
return merge(left, right)
基数排序
import math
def radix_sort(lists, radix = 10):
k = int(math.ceil(math.log(max(lists), radix)))
bucket =[[] for i in range(radix)]
for i in range(1, k + 1):
for j in lists:
bucket[j / (radix**(i - 1)) % (radix**i)].append(j)
del lists[:]
for z in bucket:
lists += z
del z[:]
return lists