345. Reverse Vowels of a String

class Solution {public:    bool isV(char c)    {        return c=='a'||c=='e'||c=='i'||c=='o'||c=='u'||c=='A'||c=='E'||c=='I'||c=='O'||c=='U';    }    string reverseVowels(string s) {        int n=s.size();        int i=0,j=n-1;        while(i<j)        {            while(i<j&&!isV(s[i]))                i++;            while(i<j&&!isV(s[j]))                j--;            swap(s[i],s[j]);            i++;            j--;        }        return s;    }};