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.
public class Solution {
public bool HalvesAreAlike(string s) {
int vowel = 0;
for(int i=0;i<s.Length/2;i++){
if(IsVowel(s[i])){
vowel++;
}
}
for(int i=s.Length/2;i<s.Length;i++){
if(IsVowel(s[i])){
vowel--;
}
}
return vowel==0;
}
private bool IsVowel(char ch){
if(ch=='a'||ch=='A'||ch=='e'||ch=='E'||ch=='i'||ch=='I'||ch=='o'||ch=='O'||ch=='u'||ch=='U'){
return true;
}
return false;
}
}Time Complexity: O(n)
Space Complexity: O(1)
