2 quick lessons from a C# coding exercise

This simple problem reminded me not to overthink — unless you have to.

Coding exercise time.

I still like doing coding exercises, even after years of programming. I recently came across this neat exercise — a simplified Pythagorean triplet — that reminded me not to overthink problems until you really have to.

Fair warning — this is not a hard problem. But I want to remember these takeaways:

(1) You don’t always need to do a lot of work to figure out a good complexity algorithm for a problem. Sometimes we want to grab our favorite data structures right away, but sometimes also reworking the problem can cut down the complexity.

(2) A good guess is often good enough — e.g. working out better ranges for loops is sometimes not even worth it, and even a simple guess will suffice until we really have to solve it.

The problem

The Pythagorean triple is three positive integers a,b,c that satisfy:

A common coding exercise is to efficiently find all a,b,c that are each less than N that satisfy this equation (emphasis on efficiently).

A simplified version of this problem is to consider another condition:

This addition greatly simplifies the problem, and a very efficient algorithm can be easily…