排序算法

冒泡

a=[111,22,233,12,3,4]
print a[::-1]
def bubbleSort(alist):
    for passnum in range(len(alist)-1,0,-1):
        print alist,passnum 
        for i in range(passnum):
            if alist[i]>alist[i+1]:
                temp = alist[i]
                alist[i] = alist[i+1]
                alist[i+1] = temp
    return alist
   
print bubbleSort(a)

详细分析

a=[111,22,233,12,33,4]
print a[::-1]
def bubbleSort(alist):
    for passnum in range(len(alist)-1,0,-1):
        print alist,passnum,'!!!!!!!!'
        for i in range(passnum):
           
            if alist[i]>alist[i+1]:
               alist[i] ,alist[i+1] = alist[i+1] , alist[i]
               print a[i+1],'is bigger then',a[i],'so changed'
               print alist
              
            else:
                print a[i],'is not bigger then',a[i+1],'so no changed'
                print alist 
    return alist
   
print bubbleSort(a)结果

[111, 22, 233, 12, 33, 4] 5 !!!!!!!!

111 is bigger then 22 so changed

[22, 111, 233, 12, 33, 4]

111 is not bigger then 233 so no changed

[22, 111, 233, 12, 33, 4]

233 is bigger then 12 so changed

[22, 111, 12, 233, 33, 4]

233 is bigger then 33 so changed

[22, 111, 12, 33, 233, 4]

233 is bigger then 4 so changed

[22, 111, 12, 33, 4, 233]

[22, 111, 12, 33, 4, 233] 4 !!!!!!!!

22 is not bigger then 111 so no changed

[22, 111, 12, 33, 4, 233]

111 is bigger then 12 so changed

[22, 12, 111, 33, 4, 233]

111 is bigger then 33 so changed

[22, 12, 33, 111, 4, 233]

111 is bigger then 4 so changed

[22, 12, 33, 4, 111, 233]

[22, 12, 33, 4, 111, 233] 3 !!!!!!!!

22 is bigger then 12 so changed

[12, 22, 33, 4, 111, 233]

22 is not bigger then 33 so no changed

[12, 22, 33, 4, 111, 233]

33 is bigger then 4 so changed

[12, 22, 4, 33, 111, 233]

[12, 22, 4, 33, 111, 233] 2 !!!!!!!!

12 is not bigger then 22 so no changed

[12, 22, 4, 33, 111, 233]

22 is bigger then 4 so changed

[12, 4, 22, 33, 111, 233]

[12, 4, 22, 33, 111, 233] 1 !!!!!!!!

12 is bigger then 4 so changed

[4, 12, 22, 33, 111, 233]

[4, 12, 22, 33, 111, 233]