Python选择排序、冒泡排序、合并排序代码实例

前两天刚装了python 3.1.1, 禁不住技痒写点code。
1.选择排序

>>> def SelSort(L):

    length=len(L)

    for i in range(length-1):

        minIdx=i

        minVal=L[i]

        j=i+1

        while j<length:

            if minVal>L[j]:

                minIdx=j

                minVal=L[j]

            j=j+1

        L[i],L[minIdx]=L[minIdx],L[i]

    return L

2.冒泡排序

>>> def bubSort(L):

    swapped=True

    while swapped:

        swapped=False

        for i in range(len(L)-1):

            if L[i]>L[i+1]:

                L[i],L[i+1]=L[i+1],L[i]

                swapped=True

    return L

>>> def merge(left,right):

    result=[]

    i,j=0,0

    while i<len(left) and j<len(right):

        if left[i]<=right[j]:

            result.append(left[i])

            i=i+1

        else:

            result.append(right[j])

            j=j+1

    result+=left[i:]

    result+=right[j:]

    return result

>>> def mergesort(L):

    if len(L) < 2:

        return L

    else:

        middle = int(len(L)/2)

        left = mergesort(L[:middle])

        right = mergesort(L[middle:])

        return merge(left, right)