Merge_sort

"""
Created on Thu Oct 09 17:32:31 2014

@author: Zharma

Describe: input:A 要排序的序列
                p 要排序的起始元素下标
                r 要排序的最后一个元素的下标
          排序内容可以为A的全部序列或者部分序列

"""

def merge(A, p, q, r):
    L = A[p: q + 1]
    R = A[q + 1: r + 1]
    print R
    L.append('None')
    R.append('None')
    i = 0
    j = 0
    for e in range(p, r + 1):
        if L[i] <= R[j]:
            A[e] = L[i]
            i += 1
    else:
        A[e] = R[j]
        j += 1


def merge_sort(A, p, r):
    if p < r:
        q = (p + r)/2
        merge_sort(A, p, q)
        merge_sort(A, q + 1, r)
        merge(A, p, q, r)

偶尔有时间,来一发算法,自娱自乐