Motivation

The other day, I was solving a leetcode question. I was using Python, but somehow, I can not pass the OA, although it ran pretty fine in “run code against your own input”.

Long story short: I decided to use Go to write the solution. While trying to write a helper function (a nested recursive function), I found some interesting things about functions in Go, which I think are worth sharing.

Write a nested recursive sum

To ignore the needless complex logic, I will use sum function in this article instead of the original one. It takes a single argument k , return the sum from natural number k to 1. For instance, sum(3) should be 6 , since3 + 2 + 1 equals to 6 .

Anyway, here is the pattern: a global function called sum , in which a helper function is defined, which will invoke it self to produce the result recursively. The sum function invokes helper to start the recursion.

#golang #recursion #go #functional-programming