1704. Determine if String Halves Are Alike
给你一个字串，问你他的前后两半是否相似。
相似的定义为拥有同样数量的元音(包含aeiouAEIOU)。
Example 1:
Input: s = "book"
Output: true
Explanation: a = "bo" and b = "ok". a has 1 vowel and b has 1 vowel.
Example 2:
Input: s = "textbook"
Output: false
Explanation: a = "text" and b = "book". a has 1 vowel whereas b has 2.
思路:
1.切一半，Counter()，把元音数量的差距加起来看是不是0，没了
class Solution:
def halvesAreAlike(self, s: str) -> bool:
n = len(s)
a = Counter(s[:n//2])
b = Counter(s[n//2:])
return sum([a[c] - b[c] for c in 'aeiouAEIOU']) == 0
又是开心水题的一天