Daily LeetCode – day0105 1704. Determine if String Halves Are Alike

import java.util.HashSet;
import java.util.Set;

// 1704. Determine if String Halves Are Alike
class Solution {
    public boolean halvesAreAlike(String s) {
        Set<Character> vowels = new HashSet<>();
        vowels.add('a');
        vowels.add('e');
        vowels.add('i');
        vowels.add('o');
        vowels.add('u');
        vowels.add('A');
        vowels.add('E');
        vowels.add('I');
        vowels.add('O');
        vowels.add('U');
        int len = s.length();
        int leftVowels = 0;
        for (int i = 0; i < len / 2; ++i) {
            if (vowels.contains(s.charAt(i))) {
                ++leftVowels;
            }
        }
        int rightVowels = 0;
        for (int i = len / 2; i < len; ++i) {
            if (vowels.contains(s.charAt(i))) {
                ++rightVowels;
            }
        }
        return leftVowels == rightVowels;
    }
}

学习笔记：
这是一道字符串的简单题，用到的是哈希表。