Problem of the Day

Problem:

Consider the following recursive method.

/**
 * PRECONDITION: m is positive, and n >= 0
 */
public static int helper(int m, int n)
{
    if (n == 0)
        return 1;
    else
        return m * helper(m, n - 1);
}

Which of the following operations does the method helper implement?

calculating a power, mⁿ
integer division, m / n
integer division, m % n
integer multiplication, m * n

Show solution:

The correct answer is a. Successive calls to the method helper are made with decreasing values of n, with each call returning the product of m with the results of all future calls of helper.