常用排序算法的Python实现

Python

• 常用排序算法的Python实现
  • 冒泡排序
  • 选择排序
  • 插入排序
  • 希尔排序

#/usr/bin/python
# -*- coding: UTF-8 -*-
#
#pip install numpy
#pip install scipy
#pip install matplotlib
import matplotlib.pyplot as plt
import numpy as np
x = np.linspace(1, 100, 10)
y1 = np.power(x, 2)
plt.plot(x, y1, 'r-o', label='n^2')
y2 = np.multiply(x, np.log2(x))
plt.plot(x, y2, 'g-^', label='nlog2n')
y2 = np.multiply(x, np.log(x))
plt.plot(x, y2, 'b-+', label='nlogn')
plt.legend()
plt.xlabel('nums')
plt.ylabel('time')
plt.title('mean time complexity')
plt.show()

冒泡排序

def bubble_sorts(list):
    count = len(list)
    for i in range(0, count-1):
        for j in range(0, count-1-i):
            if list[j] > list[j+1]:
                list[j], list[j+1] = list[j+1], list[j]
    return list

选择排序

def select_sort(list):
    count = len(list)
    for i in range(0, count - 1):
        max = 0
        for j in range(0, count - 1 - i):
            if list[max] < list[j + 1]:
                max = j + 1
        list[max], list[count - 1 - i] = list[count - 1 - i], list[max]
    return list

插入排序

def insert_sort(list):
    count = len(list)
    for i in range(1, count):
        current = list[i]
        pos = i
        while pos > 0 and list[pos - 1] > current:
            list[pos] = list[pos - 1]
            pos = pos - 1
        list[pos] = current
    return list

希尔排序

def shell_sort(list):
    count = len(list)
    step = count / 2
    while step > 0:
        for i in range(step, count):
            current = list[i]
            pos = i
            while pos > 0 and list[pos - step] > current:
                list[pos] = list[pos - step]
                pos = pos - step
            list[pos] = current
        step = step / 2
    return list