Skip to Content
Learning JavaScript Data Structures and Algorithms - Third Edition
book

Learning JavaScript Data Structures and Algorithms - Third Edition

by Loiane Avancini
April 2018
Beginner to intermediate content levelBeginner to intermediate
426 pages
10h 19m
English
Packt Publishing
Content preview from Learning JavaScript Data Structures and Algorithms - Third Edition

Recursive factorial

Now, let’s try rewriting the factorialIterative function using recursion. But first, let’s define all the steps using a recursive definition.

The factorial of 5 is computed by 5 * 4 * 3 * 2 * 1. The factorial of 4 (n -1) is computed by 4 * 3 * 2 * 1. Computing (n - 1) is a subproblem we solve to compute n!, which is the original problem, so we can define the factorial of 5 as follows:

  1. factorial(5) = 5 * factorial(4): We can compute 5! as 5 * 4!.
  2. factorial(5) = 5 * (4 * factorial(3)): We need to solve the subproblem of computing 4!, which we can compute as 4 * 3!.
  3. factorial(5) = 5 * 4 * (3 * factorial(2)): We need to solve the subproblem of computing 3!, which we can compute as 3 * 2!.
  4. factorial(5) = 5 * 4 * 3 * (2 * factorial(1)) ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

Learning JavaScript Data Structures and Algorithms

Learning JavaScript Data Structures and Algorithms

Loiane Avancini

Publisher Resources

ISBN: 9781788623872Supplemental Content