Find longest sequence of zeros in binary representation of an integer.

BinaryLongestZeroSequence.java

/**
 *
Find longest sequence of zeros in binary representation of an integer.
*/

public class BinaryLongestZeroSequence {
    /**
     * worst-case time complexity is O(log(N));
     * number of bits = log(N) ==> worst case is O(N)
     * @param N
     * @return
     */
    public int solution(int N) {
        // write your code in Java SE 8
//        System.out.println("input: " + N);

        String binaryString = Integer.toBinaryString(N);
        char[] binaries = binaryString.toCharArray();

        boolean startedSequence = false;

        int currentLength = -1;
        int maxLength = 0;

        for(char bit : binaries){
//            System.out.print(bit + " ");

            if(bit == '0') {
                if(startedSequence){
                    currentLength ++;
                }
            }
            else if(bit == '1') {
                if(startedSequence == false) {
                    startedSequence = true;
                }
                else{
                    if(maxLength < currentLength){
                        maxLength = currentLength;
                    }
                }
                currentLength = 0;

            }
        }

//        System.out.println("Length for "+ N + " is " + maxLength);
        return maxLength;
    }


    public static void main (String[] args){

        BinaryLongestZeroSequence algo = new BinaryLongestZeroSequence();

        validate(algo, 1041, 5);

        validate(algo, 8, 0);
        validate(algo, 529, 4);
        validate(algo, 20, 1);
        validate(algo, 15, 0);
        validate(algo, 9, 2);

    }


    private static void validate(BinaryLongestZeroSequence algo, int N, int sequenceLength){
        System.out.println("==========");

        if( sequenceLength == algo.solution(N))
            System.out.println("PASS " + N);
        else
            System.out.println("FAIL " + N);

    }

}