用Python实现各种排序算法

1.冒泡排序

def bubble(list):
    for i in range(len(list)):
        for j in range(0,len(list)-1-i):
            if list[j] > list[j+1]:
                list[j],list[j+1]=list[j+1],list[j]
if name == 'main':
    list1 = [2,3,5,7,8,9,6,54,1,42]
    bubble(list1)
    print(list1)

2.插入排序

def insertsort(list):
    if list != None:
        if len(list) == 1:
            pass
        else:
            for i in range(1,len(list)):#start with second item.
                temp = list[i]
                for j in range(i):
                    if list[j]>list[i]:
                        for k in range(i,j,-1):#
                            list[k]= list[k-1]
                        list[j] = temp
if name == 'main':
    list1 = [3,2,42]
    insertsort(list1)
    print(list1)

3.快速排序

L = [90,89,78,67,56,45,34,23,12,0]
def first_sort(numbers,i,j):
    temp = numbers[i]
    while i!=j:
        while i<j and numbers[j]>temp:
            j = j - 1
        if i < j
            numbers[i] = numbers[j]
            i = i + 1
        while i < j and numbers[i]<temp:
            i = i + 1
        if i <j:
            numbers[j] = numbers[i]
            j = j - 1
        numbers[i] = temp
        return i
def quick_sort(numbers,j):
    if i<j:
        middle = first_sort(numbers,j)
        quick_sort(numbers,middle-1)
        quick_sort(numbers,middle+1,j)
if name=='main':
    quick_sort(L,len(L)-1)
    print

4.选择排序

def selectionsort(list):
    if list != None:
        for i in range(len(list)):
            min = i
            for j in range(i+1,len(list)):
                if list[min] > list[j]:
                    min = j
            if min != i:
                list[min],list[i] = list[i],list[min]
if name == 'main':
    list1 = [2,42]
    selectionsort(list1)
    print(list1)

5.希尔排序

test=[9,7]
def ShellSort(data,flag):
    '''
    data: list,to be sorted
    flag: 0->asc,1->desc
    return a new sorted list
    '''
    retData=[]
    #copy data to retData
    for item in data:
        retData.append(item)
    #sort retData
    count=len(retData)
    step=count/2;
    while step>0:
        i=0
        while i<count:
            j=i+step
            while j<count:
                t=retData.pop(j)
                k=j-step
                #asc
                if flag==0:
                    while k>=0:
                        if t>=retData[k]:
                            retData.insert(k+1,t)
                            break
                        k=k-step
                    if k < 0:
                        retData.insert(0,t)
                #desc
                elif flag==1:
                    while k>=0:
                        if t<=retData[k]:
                            retData.insert(k+1,t)
                            break
                        k=k-step
                    if k<0:
                        retData.insert(0,t)
                j=j+step
            i=i+1
        step=step/2
    return retData
data=ShellSort(test,0)
print 'Asc:',data
data=ShellSort(test,1)
print 'Desc:',data