1704. Determine if String Halves Are Alike

# 1704. Determine if String Halves Are Alike#

## 题目 #

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.

## 解题思路 #

• 简单题。依题意，分别统计前半段元音字母的个数和后半段元音字母的个数，个数相同则输出 true，不同就输出 false。

## 代码 #

``````package leetcode

func halvesAreAlike(s string) bool {
return numVowels(s[len(s)/2:]) == numVowels(s[:len(s)/2])
}

func numVowels(x string) int {
res := 0
for _, c := range x {
switch c {
case 'a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U':
res++
}
}
return res
}
``````

Nov 25, 2022