【代码】排序算法python全实现（冒泡、插入、选择、睡眠...）
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文章目录
- 冒泡排序
- 插入排序
- 选择排序
- 归并排序
- 快速排序
- 计数排序
冒泡排序
import time
def bubble_sort(array):
length = len(array)
if length <= 1:
return
for i in range(length):
made_swap = False
for j in range(length - 1 - i):
if array[j] > array[j + 1]:
array[j], array[j + 1] = array[j + 1], array[j]
made_swap = True
if not made_swap:
break
if __name__ == '__main__':
array = [5, 6, -1, 4, 2, 8, 10, 7, 6]
start = time.clock()
bubble_sort(array)
print(array)
end = time.clock()
print('用时：', str(end - start))
插入排序
import time
def insertion_sort(array):
length = len(array)
if length <= 1:
return
for i in range(1, length):
value = array[i]
j = i - 1
while j >= 0 and array[j] > value:
array[j + 1] = array[j]
j -= 1
array[j + 1] = value
if __name__ == '__main__':
array = [5, 6, -1, 4, 2, 8, 10, 7, 6]
start = time.clock()
insertion_sort(array)
print(array)
end = time.clock()
print('用时：', str(end - start))
选择排序
import time
def insertion_sort(array):
length = len(array)
if length <= 1:
return
for i in range(length):
min_index = i
min_val = array[i]
for j in range(i, length):
if array[j] < min_val:
min_val = array[j]
min_index = j
array[i], array[min_index] = array[min_index], array[i]
if __name__ == '__main__':
array = [5, 6, -1, 4, 2, 8, 10, 7, 6]
start = time.clock()
insertion_sort(array)
print(array)
end = time.clock()
print('用时：', str(end - start))
归并排序
import time
def merge_sort(array):
merge_out(array, 0, len(array) - 1)
def merge_out(array, low, high):
if low < high:
mid = low + (high - low) // 2
merge_out(array, low, mid)
merge_out(array, mid + 1, high)
merge_in(array, low, mid, high)
def merge_in(array, low, mid, high):
# a[low:mid], a[mid+1, high] are sorted.
i, j = low, mid + 1
tmp = []
while i <= mid and j <= high:
if array[i] <= array[j]:
tmp.append(array[i])
i += 1
else:
tmp.append(array[j])
j += 1
# 将超出索引未添加进tmp的添加进去
if i <= mid: # 如果mid右边已添加，则需补充mid左边部分
start, end = i, mid
else:
start, end = j, high
tmp.extend(array[start:end + 1]) # 常规+1
array[low:high + 1] = tmp
if __name__ == '__main__':
array = [5, 6, -1, 4, 2, 8, 10, 7, 6]
start = time.clock()
merge_sort(array)
print(array)
end = time.clock()
print('用时：', str(end - start))
快速排序
import time
import random
def quick_sort(array):
quick_out(array, 0, len(array) - 1)
def quick_out(array, low, high):
if low < high:
k = random.randint(low, high)
array[low], array[k] = array[k], array[low] # 将分区点换到首位，避免了K的传参
m = partition(array, low, high)
quick_out(array, low, m - 1)
quick_out(array, m + 1, high)
# 返回pivot正确的位置索引（它的左边是比它小的，右边是比它大的）
def partition(array, low, high):
pivot, j = array[low], low # j指向pivot在的位置
for i in range(low + 1, high + 1): # i指向待比较元素的位置，从pivot后一位开始，因为pivot在首位
if array[i] <= pivot:
j += 1 # 此时j指向pivot应该在的位置
array[j], array[i] = array[i], array[j] # 先让待比较的元素交换位置
array[low], array[j] = array[j], array[low] # 真实交换pivot到它正确的位置
return j
if __name__ == '__main__':
array = [5, 6, -1, 4, 2, 8, 10, 7, 6]
start = time.clock()
quick_sort(array)
print(array)
end = time.clock()
print('用时：', str(end - start))
计数排序
import time
def counting_sort(array):
if len(array) <= 1:
return
counts = [0] * (max(array) + 1)
for num in array:
counts[num] += 1
# 临时数组，储存排序之后的结果
array_sorted = []
for i in range(max(array) + 1):
array_sorted += [i] * counts[i]
array[:] = array_sorted
if __name__ == '__main__':
array = [5, 6, 1, 4, 2, 8, 10, 7, 6]
start = time.clock()
counting_sort(array)
print(array)
end = time.clock()
print('用时：', str(end - start))