Inspired by this question I've come up with a solution of my own. The task is to find longest sequence of zeroes surrounded by ones in a binary representations of an integer (e.g. 1041 == 0b10000010001, thus the answer is 5). The task also requires the complexity of \$O(log(N))\$. As far as I understand it means that it means linear complexity in terms of digits, whose number is \$log(N)\$. Am I correct in this conclusion?

private int biggestBinaryGap(int n) {
    while (endsWithZero(n))
        n >>= 1;
    return biggestBinaryGapRec(n >> 1);
}

private int biggestBinaryGapRec(int n) {
    if (n == 0)
        return 0;

    int gap = 0;
    for (; endsWithZero(n); n >>= 1, gap++);
    return Math.max(gap, biggestBinaryGapRec(n >> 1));

}

private boolean endsWithZero(int n) {
    return n > 0 && (n & 1) == 0;
}