A Common-Sense Guide to Data Structures and Algorithms, Second Edition, 2nd Edition

Exercises

The following exercises provide you with the opportunity to practice with recursion. The solutions to these exercises are found in the section, ​Chapter 10​.

1. The following function prints every other number from a low number to a high number. For example, if low is 0 and high is 10, it would print:

   0
   2
   4
   6
   8
   10

   Identify the base case in the function:

   def print_every_other(low, high)
     return if low > high
     puts low
     print_every_other(low + 2, high)
   end

2. My kid was playing with my computer and changed my factorial function so that it computes factorial based on (n - 2) instead of (n - 1). Predict what will happen when we run factorial(10) using this function:

   def factorial(n)
     return 1 if n == 1
     return ...