Recursion problem — Sum of N natural numbers
Natural numbers are those numbers which start with 1. So, if we say the sum of 10 natural numbers, it means that we need to find the sum from 1 to 10.
If you’re not aware, this is the sixth article of the recursion series. Previous articles were about the concept of recursion and some snippet output exercises. Get the complete list of the series here: https://medium.com/the-ds-man/a-series-on-recursion-478aa3d3d88
Problem
For a given input N, write a recursive function which will compute the sum of N natural numbers.
Don’t move onto solution until you try this yourself. I would suggest to draw diagrams like we did in previous articles. It will help to think clearly.
Solution
This problem can be solved via a simple formula with O(1) complexity. But the purpose of introducing this problem is to solve it via recursion to make the topic more clear.
Think of a base case. Since the sum we have to find is of natural numbers, so if the number reaches 1, we can return 1. And then we can add the values together.
Go solution
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Java solution
That’s all for this problem. If you have done it yourself, it’s great. If not, don’t worry. We will do a lot more.
Read further
This was the sixth article of recursion series. You can find the list of complete recursion series here: https://medium.com/the-ds-man/a-series-on-recursion-478aa3d3d88
That’s all Folks !!!
