经典排序算法python实现
目录
1. 插入排序
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直接插入排序
#!/usr/bin/env python
# -*- coding:UTF-8 -*-
# AUTHOR: YancyKahn
# FILE: D:\Work\408_863\DataStruct\Sorting\Insertion sort\base\main.py
# DATE: 2019/10/06 Sun
# TIME: 14:51:27
# DESCRIPTION: Generate infomation when a new file is created
#summary: Directly insertion sorting
#description: ascending
#argument:
#return:
#note:
class InsertionSort:
def __init__(self, lst):
self.lst = lst
def Directly_insert_sorting(self):
A = self.lst
for i in range(1, len(A)):
scout = A[i]
j = i - 1
while j > -1 and A[j] > A[i]:
A[j + 1] = A[j]
j = j - 1
A[j + 1] = scout
self.lst = A
def show(self):
return self.lst
if __name__ == "__name__":
ist = InsertionSort([5, 4, 3, 2, 1])
ist.Directly_insert_sorting()
print(ist.show())
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二分插入排序
#!/usr/bin/env python
# -*- coding:UTF-8 -*-
# AUTHOR: YancyKahn
# FILE: D:\Work\408_863\DataStruct\Sorting\Insertion sort\base1\main.py
# DATE: 2019/10/06 Sun
# TIME: 15:09:12
# DESCRIPTION: Generate infomation when a new file is created
#summary: binary insertion sorting
#description:
#argument:
#return:
#note:
class InsertSort:
def __init__(self, lst):
self.lst = lst
def BinaryInsertSort(self):
A = self.lst
for i in range(1, len(A)):
scout = A[i]
low = 0
high = i - 1
#binary search
while (low <= high):
mid = (int)((low + high)/2)
if (A[mid] > scout):
high = mid - 1
else:
low = mid + 1
j = i - 1
while j > high:
A[j + 1] = A[j]
j = j - 1
A[j + 1] = scout
self.lst = A
def show(self):
return self.lst
if __name__ == "__main__":
bst = InsertSort([5, 4, 3, 2, 1])
print(bst.show())
bst.BinaryInsertSort()
print(bst.show())
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希尔排序
#!/usr/bin/env python
# -*- coding:UTF-8 -*-
# AUTHOR: YancyKahn
# FILE: D:\Work\408_863\DataStruct\Sorting\Insertion sort\base2\main.py
# DATE: 2019/10/06 Sun
# TIME: 15:23:12
# DESCRIPTION: Generate infomation when a new file is created
#summary: shell sort
#description:
#argument:
#return:
#note:
class ShellSort:
def __init__(self, lst):
self.lst = lst
def shell_sort(self):
length = len(self.lst)
gap = (int)(length/2) #gap
arr = self.lst
while gap > 0:
for i in range(gap, length):
scout = arr[i]
j = i
while j >= gap and arr[j - gap] > scout:
arr[j] = arr[j - gap]
j -= gap
arr[j] = scout
gap = (int)(gap/2)
self.lst = arr
def show(self):
return self.lst
if __name__ == "__main__":
arr = [1, 2, 3, 4, 5]
arr.reverse()
sst = ShellSort(arr)
print(sst.show())
sst.shell_sort()
print(sst.show())
2. 交换排序
-
冒泡排序
#!/usr/bin/env python
# -*- coding:UTF-8 -*-
# AUTHOR: YancyKahn
# FILE: D:\Work\408_863\DataStruct\Sorting\Swap sort\Bubble sort\base\main.py
# DATE: 2019/10/06 Sun
# TIME: 15:56:39
# DESCRIPTION: Generate infomation when a new file is created
#summary: bubble sort
#description:
#argument:
#return:
#note:
class BubbleSort:
def __init__(self, lst):
self.lst = lst
def swap(self, i, j):
tmp = self.lst[i]
self.lst[i] = self.lst[j]
self.lst[j] = tmp
def sort(self):
for i in range(len(self.lst)):
for j in range(i, len(self.lst)):
if self.lst[i] > self.lst[j]:
self.swap(i, j)
def show(self):
return self.lst
if __name__ == "__main__":
bst = BubbleSort([5, 4, 3, 2, 1])
print(bst.show())
bst.sort()
print(bst.show())
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快速排序
#!/usr/bin/env python
# -*- coding:UTF-8 -*-
# AUTHOR: YancyKahn
# FILE: D:\Work\408_863\DataStruct\Sorting\Swap sort\Quick sort\base\main.py
# DATE: 2019/10/06 Sun
# TIME: 16:03:35
# DESCRIPTION: Generate infomation when a new file is created
#summary: quick sorting
#description:
#argument:
#return:
#note:
class QuickSort:
def __init__(self, lst):
self.lst = lst
def partition(self, low, high):
pivot = self.lst[low]
while low < high:
while low < high and self.lst[high] >= pivot:
high = high - 1
self.lst[low] = self.lst[high]
while low < high and self.lst[low] <= pivot:
low = low + 1
self.lst[high] = self.lst[low]
self.lst[low] = pivot
return low
def quick_sort_helper(self, low, high):
if low < high:
pivotpos = self.partition(low, high)
self.quick_sort_helper(low, pivotpos - 1)
self.quick_sort_helper(pivotpos + 1, high)
def quick_sort(self):
self.quick_sort_helper(0, len(self.lst) - 1)
def show(self):
return self.lst
if __name__ == "__main__":
qst = QuickSort([5, 4, 3, 2, 1])
print(qst.show())
qst.quick_sort()
print(qst.show())
3. 选择排序
-
简单选择排序
#!/usr/bin/env python
# -*- coding:UTF-8 -*-
# AUTHOR: YancyKahn
# FILE: D:\Work\408_863\DataStruct\Sorting\Select sort\Easy Select sort\base\main.py
# DATE: 2019/10/06 Sun
# TIME: 16:21:11
# DESCRIPTION: Generate infomation when a new file is created
#summary: easy select sorting
#description:
#argument:
#return:
#note:
class SelectSort:
def __init__(self, lst):
self.lst = lst
def sort(self):
for i in range(len(self.lst)):
min = i
for j in range(i + 1, len(self.lst)):
if self.lst[i] > self.lst[j]:
min = j
if min != i:
self.lst[i], self.lst[min] = self.lst[min], self.lst[i]
def show(self):
return self.lst
if __name__ == "__main__":
sst = SelectSort([5, 4, 3, 2, 1])
print(sst.show())
sst.sort()
print(sst.show())
-
堆排序
#!/usr/bin/env python
# -*- coding:UTF-8 -*-
# AUTHOR: YancyKahn
# FILE: D:\Work\408_863\DataStruct\Sorting\Select sort\Heap sort\base\main.py
# DATE: 2019/10/06 Sun
# TIME: 16:27:37
# DESCRIPTION: Generate infomation when a new file is created
#summary: heap sorting
#description:
#argument:
#return:
#note:
class HeapSort:
def __init__(self, lst):
self.lst = lst
# adjust bigest element to root. in-ordering
def traverse0(self, strat, end):
root = strat
while (root * 2 + 1) <= end:
lchild = root * 2
rchild = root * 2 + 1
swap = root
if self.lst[lchild] > self.lst[swap]:
swap = lchild
if self.lst[rchild] > self.lst[swap]:
swap = rchild
if swap != root:
self.lst[swap], self.lst[root] = self.lst[root], self.lst[swap]
root = swap
else:
return
# adjust smallest element to root. in-ordering
def traverse1(self, strat, end):
root = strat
while (root * 2 + 1) <= end:
lchild = root * 2
rchild = root * 2 + 1
swap = root
if self.lst[lchild] < self.lst[swap]:
swap = lchild
if self.lst[rchild] < self.lst[swap]:
swap = rchild
if swap != root:
self.lst[swap], self.lst[root] = self.lst[root], self.lst[swap]
root = swap
else:
return
# mod = 0 --> big heap(default), mod = 1 small heap.
def heapify(self, mod = 0):
length = len(self.lst)
start = (int)(length/2)
while start > -1:
print(self.show())
if mod == 0:
self.traverse0(start, length - 1)
else:
self.traverse1(start, length - 1)
start -= 1
# mod = 0 --> ascending, mod = 1 --> descending
def sort(self, mod = 0):
print("heapify: ")
print("----------")
self.heapify(mod)
print(self.show())
print("----------")
if mod == 0:
end = len(self.lst) - 1
while end > 0:
print(self.show())
self.lst[end], self.lst[0] = self.lst[0], self.lst[end]
end -= 1
self.traverse0(0, end)
else:
end = len(self.lst) - 1
while end > 0:
print(self.show())
self.lst[end], self.lst[0] = self.lst[0], self.lst[end]
end -= 1
self.traverse1(0, end)
def show(self):
return self.lst
if __name__ == "__main__":
hst0 = HeapSort([5, 109, 87, 4, 50, 908, 65, 22, 1, 36])
print("smallest heap:")
hst0.sort()
print(hst0.show())
hst1 = HeapSort([5, 109, 87, 4, 50, 908, 65, 22, 1, 36])
print("bigest heap:")
hst1.sort(mod = 1)
print(hst1.show())
4. 其他排序
-
归并排序
#!/usr/bin/env python
# -*- coding:UTF-8 -*-
# AUTHOR: YancyKahn
# FILE: D:\Work\408_863\DataStruct\Sorting\Merge sort\base\main.py
# DATE: 2019/10/06 Sun
# TIME: 17:25:51
# DESCRIPTION: Generate infomation when a new file is created
#summary: merge sort
#description:
#argument:
#return:
#note:
class MergeSort:
def __init__(self, lst):
self.lst = lst
def merge(self, left, right):
leftcout, rightcout = 0, 0
output = list()
while leftcout < len(left) or rightcout < len(right):
if leftcout < len(left) and rightcout < len(right):
if left[leftcout] < right[rightcout]:
output.append(left[leftcout])
leftcout += 1
else:
output.append(right[rightcout])
rightcout += 1
if leftcout == len(left) and rightcout < len(right):
output.append(right[rightcout])
rightcout += 1
elif rightcout == len(right) and leftcout < len(left):
output.append(left[leftcout])
leftcout += 1
return output
def merge_sort(self, a):
midcount = len(a) // 2
if len(a) > 1:
left = self.merge_sort(a[midcount:])
right = self.merge_sort(a[:midcount])
return self.merge(left, right)
return a
def sort(self):
a = self.merge_sort(self.lst)
self.lst = a
def show(self):
return self.lst
if __name__ == "__main__":
mst = MergeSort([3, 1, 4, 5, 6, 7, 8])
print(mst.show())
mst.sort()
print(mst.show())
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基数排序
#!/usr/bin/env python
# -*- coding:UTF-8 -*-
# AUTHOR: YancyKahn
# FILE: D:\Work\408_863\DataStruct\Sorting\Radix sort\base\main.py
# DATE: 2019/10/06 Sun
# TIME: 18:21:47
# DESCRIPTION: Generate infomation when a new file is created
#summary: Radix sort
#description:
#argument:
#return:
#note:
from collections import defaultdict
class RadixSort:
def __init__(self, lst):
self.lst = lst
#radix sort
def radix_sort(self, eps):
bucket = defaultdict() #bucket
output = list()
for i in range(10):
bucket.setdefault(i,[])
for i in range(len(self.lst)):
index = self.lst[i]//eps
bucket[index%10].append(self.lst[i])
# bucket sort
for i in range(10):
if len(bucket) != 0:
for element in bucket[i]:
output.append(element)
self.lst = output
#sort
def sort(self):
max_value = max(self.lst)
eps = 1
while max_value//eps > 0:
self.radix_sort(eps)
eps *= 10
def show(self):
return self.lst
if __name__ == "__main__":
rst = RadixSort([311, 492, 113, 425, 631, 828, 710])
print(rst.show())
rst.sort()
print(rst.show())