python 运用库函数collections.Conter解法

解题思路:我主要说说collections.Conter()的用法.就是将元素数量统计，然后计数并返回一个类似字典的东西，键为元素，值为元素个数。看下面的一个例子                              

                 <<<from collections import Counter

                 <<<colors = ['red', 'blue', 'red', 'green', 'blue', 'blue']

                 <<<c = Counter(colors) 

                 <<<print (dict(c)

                  输出 {‘red’: 2, ‘blue’: 3, ‘green’: 1}
注意事项:

参考代码:

import collections
k = int(input())
s = input()
l = len(s)

lif l%k:
   print(-1)
else:
   ans = 0
   for i in range(0,l//k):
       lis = [s[j] for j in range(i,l,l//k)]
       d = dict(collections.Counter(lis))
       ans += (k-max(d.values()))
   print(ans)