Determine if String Halves Are Alike

#leetcode #dsa #theabbie

You are given a string s of even length. Split this string into two halves of equal lengths, and let a be the first half and b be the second half.

Two strings are alike if they have the same number of vowels ('a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U'). Notice that s contains uppercase and lowercase letters.

Return true if a and b are alike. Otherwise, return false.

Example 1:

Input: s = "book"
Output: true
Explanation: a = "bo" and b = "ok". a has 1 vowel and b has 1 vowel. Therefore, they are alike.

Example 2:

Input: s = "textbook"
Output: false
Explanation: a = "text" and b = "book". a has 1 vowel whereas b has 2. Therefore, they are not alike.
Notice that the vowel o is counted twice.

Constraints:

2 <= s.length <= 1000
s.length is even.
s consists of uppercase and lowercase letters.

SOLUTION:

class Solution:
    def halvesAreAlike(self, s: str) -> bool:
        n = len(s)
        vowels = {'a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U'}
        f = len([i for i in range(n // 2) if s[i] in vowels])
        s = len([i for i in range(n // 2, n) if s[i] in vowels])
        return f == s