HACKER Q&A
📣 shivajikobardan

How do I think about recursion in math and programming?


I got the idea for problems like factorials or finding sum from 1 to n, where there's a pattern visible. Like this:

Source:https://99x.io/blog/recursion-is-not-hard-here-is-the-right-way-to-think

I got it for things like addition, subtraction, division, multiplication of two numbers as well.

eg: a+b

=a+b-1+1

=SUM(a+1,b-1)

Now, I am wondering how it'll be for finding a palindrome of a number? I've a solution but I'm not understanding how we came towards it. I'm looking for how to come towards a solution than a solution itself.

  👤 optbuild Accepted Answer ✓
Recursion is basically the other side of the coin for mathematical induction. I would suggest that you learn a functional programming language and mathematical induction.

You can try out: How to Design Programs at https://htdp.org/ if you want to learn more about how recursion is used in programming and where.

For mathematical induction you make read:

1. What is Mathematics by Courant and Robbins

2. Introduction to Mathematical Thinking by Keith Devlin