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".
class Solution {
public:
string reverseVowels(string s) {
char arr[] = {'a', 'e','i','o','u','A','E','I','O','U'};
vector<char> v = vector<char>();
set<char> vowels = set<char>(arr, arr+10);
for(int i=0;i<s.size();i++)
if(vowels.count(s[i]) > 0)
v.push_back(s[i]);
for(int i=0,j=v.size()-1;i<s.size() && j>=0;i++)
if(vowels.count(s[i]) > 0)
s[i] = v[j--];
return s;
}
};
