src/main/java/com/fishercoder/solutions/_1704.java

package com.fishercoder.solutions;

import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
import java.util.stream.IntStream;

public class _1704 {
    public static class Solution1 {
        public boolean halvesAreAlike(String s) {
            Set<Character> vowels = new HashSet<>(Arrays.asList('a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U'));
            int firstHalfVowelsCount = (int) IntStream.range(0, s.length() / 2).filter(i -> vowels.contains(s.charAt(i))).count();
            int secondHalfVowelsCount = (int) IntStream.range(s.length() / 2, s.length()).filter(i -> vowels.contains(s.charAt(i))).count();
            return firstHalfVowelsCount == secondHalfVowelsCount;
        }
    }
}