int string_is_palindrome(char s[]) {
    int half_length;
    int length = 0;
    char *sptr = s;

    while (*sptr!='\0') {
        length++;
        sptr++;
    }
    // TEST int a = s[length-1];
    half_length = length/2;

    for (int i = 0; i < half_length; i++) {
        if (s[i] == s[length-1]) {
            length--;
        } else {
            return 0;
        }
    }

    return 1;
}