Reverse strings of vowels

Question

I have to find the vowels in an input string and return the string of the vowels in reverse order.

Example input: "woUIW"

The expected output is "IUOo"

But I cannot use pointers, only recursion.

This is my attempt:

void letters_revers(char s[])
{
    int i = 0,g,len,right,left;
    char reversed[10];
    len=strlen(reversed)-1; // get the length of the string
    left = 0; // set left index at 0
    right = len - 1; // set right index len - 1
    while(i!='\0')
    {

        if (s[i] == 'a' || s[i] == 'A' || s[i] == 'e' || s[i] == 'E' || s[i] == 'i' || s[i] == 'I' || s[i] =='o' || s[i]=='O' || s[i] == 'u' || s[i] == 'U')
        { reversed[i]+=s[i];
            for(g = len - 1; g >= 0; g--)
            {
                printf("%c", reversed[g]);
            }
        }

    }i++;
}