Decimal to Binary

/*
 * Problem : Convert a decimal number to binary.
 * Input   : One non-negative integer.
 * Output  : The binary form.
 * Approach: Divide by 2 and collect the remainders.
 * Time    : O(log n)
 * Space   : O(log n)
 * Java    : 8 or newer.
 */
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        long number = new Scanner(System.in).nextLong();

        // Step 1: Zero is written as 0. The loop below would write nothing, so we handle 0 first.
        if (number == 0) {
            System.out.println("0");
            return;
        }

        // Step 2: Collect the binary digits here. We get them from the last digit to the first digit.
        StringBuilder bits = new StringBuilder();

        // Step 3: Repeat until the number is 0.
        while (number > 0) {
            // Step 4: The remainder of the division by 2 is the next binary digit. Example: 10 % 2 = 0.
            bits.append(number % 2);

            // Step 5: Divide by 2 to go to the next digit. Example: 10 / 2 = 5.
            number = number / 2;
        }

        // Step 6: The digits are in reverse order, so we reverse them before we print.
        System.out.println(bits.reverse());
    }
}