题目:

Write a function that takes a string as input and reverse only the vowels of a string.
Example 1:Given s = "hello", return "holle".
Example 2:Given s = "leetcode", return "leotcede".
Note:The vowels does not include the letter "y".

题目的意思大概是这样的

给定一个字符串，然后兑换里面元音字母对应的位置
先写下实现的代码(javaScript版)

var reverseVowels = function(s) {  
  if(s === null || s.length === 0) {
        return s; 
   }  
  var chars = s.split('');
  var low = 0;    
  var high = s.length - 1;
  var vowels = "aeiouAEIOU";    
  var tmp;    
  while(low < high) {        
      while(low < high && vowels.indexOf(chars[low]) === -1) { 
           low++;
        }        
      while(low < high && vowels.indexOf(chars[high]) === -1) {    
        high--;        
      }       
   tmp = chars[high];        
   chars[high] = chars[low];       
   chars[low] = tmp;        
   low++;       
   high--;    
}    
return chars.join('');
};

实现思路

只要设置一个头部变量和尾部变量一直向对方逼近就可以了，直接看代码就可以看懂啦～～

ps:这是我的第一篇文章，以后会坚持更新的～～