Question

Write a complete method which returns the number of times a positive whole number must be divided by 2 to get down to 1. It should have the following heading:

public static int count2Divide(int numberToTest)

where numberToTest is the number to test. You may assume that parameter numberToTest contains a number between 1 and 1,000.

Examples:

• If numberToTest is 5, then your method should return 2, because the number 5 can be divided by 2 a total of 2 times (5 / 2 is 2, and 2 / 2 is 1).

• If numberToTest is 26, then return 4, because the number 26 can be divided by 2 a total of 4 times (26 / 2 is 13, then 13 / 2 is 6, then 6 / 2 is 3, and finally 3 / 2 is 1).

Answer 1

public class Count2Divide {

    public static int count2Divide(int numberToTest) {
        int count = 0;
        while (numberToTest > 1) {
            count++;
            numberToTest /= 2;
        }
        return count;
    }

    public static void main(String[] args) {
        System.out.println(count2Divide(5));
        System.out.println(count2Divide(26));
    }
}