【Python全栈笔记】07 [模块二] 20 Oct 冒泡排序

给出一个列表，进行冒泡排序

原理算法： 

li = [52, 37, 23, 11, 3, 1, ]

print(li)

# 每次循环，进行一次排序，列表内数字两两比较，最大的数字排到最末尾 
# 一共循环len(li) - 1 次

for i in range(len(li) - 1):
    if li[i] > li[i + 1]:
        temp = li[i]
        li[i] = li[i+1]
        li[i + 1] = temp
print(li)

for i in range(len(li) - 2):
    if li[i] > li[i + 1]:
        temp = li[i]
        li[i] = li[i+1]
        li[i + 1] = temp
print(li)

for i in range(len(li) - 3):
    if li[i] > li[i + 1]:
        temp = li[i]
        li[i] = li[i+1]
        li[i + 1] = temp
print(li)

for i in range(len(li) - 4):
    if li[i] > li[i + 1]:
        temp = li[i]
        li[i] = li[i+1]
        li[i + 1] = temp
print(li)

for i in range(len(li) - 5):
    if li[i] > li[i + 1]:
        temp = li[i]
        li[i] = li[i+1]
        li[i + 1] = temp
print(li)

'''
输出的结果：
[52, 37, 23, 11, 3, 1]
[37, 23, 11, 3, 1, 52]
[23, 11, 3, 1, 37, 52]
[11, 3, 1, 23, 37, 52]
[3, 1, 11, 23, 37, 52]
[1, 3, 11, 23, 37, 52]
'''

可以看到以上排序每次步骤一致，只有一个变量（即不用对比最后一个元素）

因此，可以再设置一个变量j, 作为循环时候的变量简化操作，由此得到：

li = [52, 37, 23, 11, 3, 1, ]
print(li)

for j in range(1, len(li)):
    for i in range(len(li) - j):
        if li[i] > li[i + 1]:
            temp = li[i]
            li[i] = li[i+1]
            li[i + 1] = temp
    print(li)
'''
结果：
[52, 37, 23, 11, 3, 1]
[37, 23, 11, 3, 1, 52]
[23, 11, 3, 1, 37, 52]
[11, 3, 1, 23, 37, 52]
[3, 1, 11, 23, 37, 52]
[1, 3, 11, 23, 37, 52]
'''