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 <= 1000

• s.length is even.

• s consists of uppercase and lowercase letters.

解題

log(n)

Runtime: 0 ms, faster than 100.00%

Memory Usage: 2.1 MB, less than 86.27%

func halvesAreAlike(s string) bool {
    
    count1 := 0
    count2 := 0
    for i:=0; i<len(s)/2; i++ {
        if isVowel(s[i]) { count1++ }
    }
    
    for i:=len(s)/2; i<len(s); i++ {
        if isVowel(s[i]) { count2++ }
    }
    
    return count1 == count2
}

func isVowel(char byte) bool {
    if char >= 'A' && char <= 'Z' {
        char += 32
    }
    
    return char == 'e' || char == 'u' || char == 'o' || char == 'a' || char == 'i'
}