1704. Determine if String Halves Are Alike

문제)

1704. Determine if String Halves Are Alike

 

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.

 

솔루션1)

class Solution:
    def halvesAreAlike(self, s: str) -> bool:
        s = s.lower()
        a = s[:len(s)//2]
        b = s[len(s)//2:]

        return self.get_vowel_count(a) == self.get_vowel_count(b)

    def get_vowel_count(self, s):
        vowels = ['a', 'e', 'i', 'o', 'u']
        c = Counter(s)

        count = 0
        for v in vowels:
            count += c.get(v, 0)

        return count

솔루션2)

class Solution:
    def halvesAreAlike(self, s: str) -> bool:
        s = s.lower()
        vowels = set('aeiou')

        c1 = 0
        c2 = 0
        for i in range(len(s)//2):
            if s[i] in vowels:
                c1 += 1
            if s[-i-1] in vowels:
                c2 += 1

        return c1 == c2