Question

I’m getting acquainted with c++ but don’t know how to compare indexed characters from the same or different strings. Here’s a palindrome example that takes an int and converts it to a string through a stringstream.

bool ispalindrome(int a) {
    stringstream stream;
    stream<<a;
    string str = stream.str();
    int length = str.length();
    int offset = length - 1;
    for (int i=0; i<=offset; i++ && offset--) {
        if (str[i] == str[i + offset]) {
            return false;
        }
        offset--;
    }
    return true;
}

For some reason this is always evaluated to false. I wouldn’t think null termination would have anything to do with it because it’s not reported by the length, so I guess I must be using the wrong comparison method. I can’t seem to find something like strncmp but with single characters.

[Edit: fixed title]

Answer 1

I don’t know how you wrote that loop, but I’m pretty sure it should be

for (int i=0; i<=offset; i++, offset--) {
    if (str[i] != str[offset]) {
        return false;
    }
}