README.md

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.

Example 3:

Input: s = "MerryChristmas"
Output: false

Example 4:

Input: s = "AbCdEfGh"
Output: true

Constraints:

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

Solutions (Ruby)

1. Solution

# @param {String} s
# @return {Boolean}
def halves_are_alike(s)
  count = 0

  (0...s.size).each do |i|
    count += i < s.size / 2 ? 1 : -1 if 'aeiouAEIOU'.include?(s[i])
  end

  count == 0
end

Solutions (Rust)

1. Solution

impl Solution {
    pub fn halves_are_alike(s: String) -> bool {
        s.bytes()
            .enumerate()
            .filter(|(_, c)| b"aeiouAEIOU".contains(c))
            .map(|(i, _)| if i < s.len() / 2 { 1 } else { -1 })
            .sum::<i32>()
            == 0
    }
}