Python實現排序算法1

排序算法有很多種，下面列舉幾種：
1.冒泡排序
2.選擇排序
3.插入排序
4.希爾排序
5.快速排序
6.歸并排序
1.冒泡排序

# -*- coding:utf-8 -*-
def bubble_sort(alist):
    """冒泡排序"""
    for  j in range(len(alist)-1):
        for i in range(0,len(alist)-1-j):
            if alist[i] > alist[i+1]:
                alist[i],alist[i+1] = alist[i+1],alist[i]
    print(alist)

if __name__ == "__main__":
    a=[10,9,81,7,6,5,41,3,2,1]
    bubble_sort(a)

# [1, 2, 3, 5, 6, 7, 9, 10, 41, 81]

2.選擇排序

# -*- coding:utf-8 -*-
def selection_sort(alist):
    """選擇排序"""
    n = len(alist)
    for i in range(n-1):
        min = i
        for j in range(i+1,n):
            if alist[min] > alist[j]:
                min = j
        alist[i],alist[min] = alist[min],alist[i]
    print(alist)

if __name__ == "__main__":
    a = [6,86,3,5,0,43,90,100]
    print(a)
    selection_sort(a)

# [6, 86, 3, 5, 0, 43, 90, 100]
# [0, 3, 5, 6, 43, 86, 90, 100]

3.插入排序

def insert_sort(alist):
    """插入排序"""
    for i in range(1,len(alist)):
        j = i
        while j > 0 :
            if alist[j] < alist[j-1]:
                alist[j-1],alist[j] = alist[j],alist[j-1]
                j -= 1
            else:
                break

if __name__ == "__main__":
    a = [6,86,3,5,0,43,90,100]
    print(a)
    insert_sort(a)
    print(a)

# [6, 86, 3, 5, 0, 43, 90, 100]
# [0, 3, 5, 6, 43, 86, 90, 100]

剩下3種算法在下一篇博客中
有問題歡迎大家給我留言