LeetCode in Kotlin

1704. Determine if String Halves Are Alike

Easy

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:

Solution

class Solution {
    fun halvesAreAlike(s: String): Boolean {
        return if (s.isEmpty()) {
            false
        } else {
            countVowel(0, s.length / 2, s) == countVowel(s.length / 2, s.length, s)
        }
    }

    private fun countVowel(start: Int, end: Int, s: String): Int {
        var c = 0
        for (i in start until end) {
            val ch = s[i]
            if (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' ||
                ch == 'u' || ch == 'A' || ch == 'E' || ch == 'I' || ch == 'O' || ch == 'U'
            ) {
                c++
            }
        }
        return c
    }
}