归并排序算法-python实现

 #-*- coding: UTF-8 -*-
 import numpy as np

 def Merge(a, f, m, l):
     i = f
     j = m + 1
     tmp = []
     while i <= m and j <= l:
         if a[i] <= a[j]:
             tmp.append(a[i])
             i += 1
         else:
             tmp.append(a[j])
             j += 1

     while i <= m:
         tmp.append(a[i])
         i += 1
     while j<= l:
         tmp.append(a[j])
         j+= 1
     i = f
     for x in xrange(0, len(tmp)):
         a[i] = tmp[x]
         i += 1

 def MergeSort(a, f, l):
     if f< l:
         m = (l + f) / 2
         MergeSort(a, f, m)
         MergeSort(a, m+1, l)
         Merge(a, f, m, l)

 if __name__ == '__main__':
     a = np.random.randint(0, 10, size = 10)
     print "Before sorting..."
     print "---------------------------------------------------------------"
     print a
     print "---------------------------------------------------------------"
     MergeSort(a, 0, a.size-1)
     print "After sorting..."
     print "---------------------------------------------------------------"
     print a
     print "---------------------------------------------------------------"