Write a function that takes a string as input and reverse only the vowels of a string.
Example 1:
Input: "hello"
Output: "holle"
Example 2:
Input: "leetcode"
Output: "leotcede"
Note:
The vowels does not include the letter "y".
345. Reverse Vowels of a String(交换元音字母)（leetcode）
原文：https://www.cnblogs.com/shaer/p/10418420.html