LeetCode Reverse Vowels of a String 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”.

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把字符串中的所有元音字母逆序。简单题，使用首尾两个指针i,j，找到元音后交换，直到i>j。 完整代码如下： [cpp] class Solution { public: string reverseVowels(string s) { unordered_set<char> vowels = { ‘a’,’e’,’i’,’o’,’u’,’A’,’E’,’I’,’O’,’U’ }; int i = 0, j = s.size() – 1; while (i < j) { while (i < j&&vowels.find(s[i]) == vowels.end())++i; if (i >= j)break; while (i < j&&vowels.find(s[j]) == vowels.end())–j; if (i >= j)break; swap(s[i++], s[j–]); } return s; } }; [/cpp] 本代码提交AC，用时52MS。]]>