Python实现针对给定字符串寻找最长非重复子串的方法

#!usr/bin/env python
#encoding:utf-8
'''''
__Author__:沂水寒城
功能：给定一个字符串，寻找最长重复子串
'''
from collections import Counter
def slice_window(one_str,w=1):
  '''''
  滑窗函数
  '''
  res_list=[]
  for i in range(0,len(one_str)-w+1):
    res_list.append(one_str[i:i+w])
  return res_list
def main_func(one_str):
  '''''
  主函数
  '''
  all_sub=[]
  for i in range(1,len(one_str)):
    all_sub+=slice_window(one_str,i)
  res_dict={}
  #print Counter(all_sub)
  threshold=Counter(all_sub).most_common(1)[0][1]
  slice_w=Counter(all_sub).most_common(1)[0][0]
  for one in all_sub:
    if one in res_dict:
      res_dict[one]+=1
    else:
      res_dict[one]=1
  sorted_list=sorted(res_dict.items(), key=lambda e:e[1], reverse=True)
  tmp_list=[one for one in sorted_list if one[1]>=threshold]
  tmp_list.sort(lambda x,y:cmp(len(x[0]),len(y[0])),reverse=True)
  #print tmp_list
  print tmp_list[0][0]
if __name__ == '__main__':
  print "测试结果："
  one_str='abcabcd'
  two_str='abcabcabd'
  three_str='bbbbbbb'
  main_func(one_str)
  main_func(two_str)
  main_func(three_str)