LeetCode-in-Java
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:
2 <= s.length <= 1000s.lengthis even.sconsists of uppercase and lowercase letters.
Solution
public class Solution {
public boolean halvesAreAlike(String s) {
if (s.isEmpty()) {
return false;
}
return countVowel(0, s.length() / 2, s) == countVowel(s.length() / 2, s.length(), s);
}
private int countVowel(int start, int end, String s) {
int c = 0;
for (int i = start; i < end; i++) {
char ch = s.charAt(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;
}
}