python排序算法-(1)冒泡排序
冒泡排序是一种简单的排序算法,其原理是比较相邻元素的大小并交换它们的位置;
每次遍历都会进行多次这样的比较和交换,直到最终得到一个有序序列。
# -*- coding: utf-8 -*-
import random
# 冒泡排序
def bubbleSort(array):
for i in range(len(array)):
# 循环比较数组元素
for j in range(len(array) - i - 1):
# 比较相邻的两个元素
# 如果要降序排列,请将 > 改为 <
if array[j] > array[j + 1]:
# 如果元素不是正确的顺序,则交换它们
temp = array[j]
array[j] = array[j + 1]
array[j + 1] = temp
# 测试
array=random.sample(range(0, 100), 50)
print("原始数组为:")
print(array)
bubbleSort(array)
print('经冒泡排序后的数组为:')
print(array)
# 优化版的冒泡排序
def bubbleSort_opt(array):
for i in range(len(array)):
num_swaps=0
# 循环比较数组元素
for j in range(len(array) - i - 1):
# 比较相邻的两个元素
# 如果要降序排列,请将 > 改为 <
if array[j] > array[j + 1]:
# 如果元素不是理想的顺序,则交换它们
temp = array[j]
array[j] = array[j + 1]
array[j + 1] = temp
# 增加 num_swaps 的值
num_swaps=num_swaps+1
if num_swaps==0:
return
# 测试
array=random.sample(range(0, 100), 50)
print("原始数组为:")
print(array)
bubbleSort_opt(array)
print('经优化的冒泡排序后的数组为:')
print(array)
运行环境:python3.8
运行结果:
原始数组为:
[86, 81, 54, 25, 60, 48, 21, 85, 39, 74, 69, 57, 24, 84, 45, 70, 12, 88, 35, 78, 50, 51, 96, 63, 4, 59, 49, 29, 9, 77, 0, 64, 36, 28, 66, 32, 18, 13, 99, 20, 14, 65, 56, 47, 19, 10, 22, 98, 37, 31]
经冒泡排序后的数组为:
[0, 4, 9, 10, 12, 13, 14, 18, 19, 20, 21, 22, 24, 25, 28, 29, 31, 32, 35, 36, 37, 39, 45, 47, 48, 49, 50, 51, 54, 56, 57, 59, 60, 63, 64, 65, 66, 69, 70, 74, 77, 78, 81, 84, 85, 86, 88, 96, 98, 99]
原始数组为:
[52, 80, 85, 56, 68, 22, 59, 50, 39, 99, 2, 51, 23, 72, 17, 0, 73, 47, 26, 76, 60, 15, 27, 61, 89, 5, 1, 18, 70, 62, 88, 95, 86, 43, 57, 82, 49, 19, 3, 87, 58, 79, 12, 10, 92, 33, 98, 65, 94, 66]
经优化的冒泡排序后的数组为:
[0, 1, 2, 3, 5, 10, 12, 15, 17, 18, 19, 22, 23, 26, 27, 33, 39, 43, 47, 49, 50, 51, 52, 56, 57, 58, 59, 60, 61, 62, 65, 66, 68, 70, 72, 73, 76, 79, 80, 82, 85, 86, 87, 88, 89, 92, 94, 95, 98, 99]