///////////////////////////////
// my solution
///////////////////////////////
int reverse(int x) {

    if (x == 0) return x;

    int xx = x;
    bool minus = false;
    if (xx < 0)
    {
        if (xx==numeric_limits<int>::min()) return 0;
        minus = true;
        xx = -1 * xx;
    }

    long long  y = 0;
    while (xx) {
        int d = xx%10;
        y = y*10 + d;
        xx = xx/10;
    }

    if (y < numeric_limits<int>::min()) return 0;
    if (y > numeric_limits<int>::max()) return 0;

    return minus ? -y : y;
}



///////////////////////////////
// improved
//////////////////////////////
int reverse(int x) {

    using LL = long long int;

    LL num = x;
    LL ans = 0;

    while (num)
    {
        ans = (ans*10) + (num%10);
        num = num/10;
        if (ans > numeric_limits<int>::max() ||
            ans < numeric_limits<int>::min() )
            return 0;
    }

    return static_cast<int>(ans);
}