Programmer's Interview 101: Print 100 'Hello World' Without Using a Loop

As I have said from the previous Programmer Interview 101 post, in every job interview for a programmer, the ability on how to formulate an algorithm on a short span of time is always tested.

"A good programmer knows how to adapt on the language because what he is capable of is generating an algorithm"

So for today, here is another question that is commonly asked on every interview.

Problem

Part 2 - Print 100 "Hello World" without using any looping code such as for, while or do-while and other similar code.

Analysis

For this example, I'll be using a C-type programming syntax.

There might be different ways here and one is the manual typing of 100 line codes of printf, if you do this then just say good bye to your prospect job. This approach are done by newbies only.

What we are about to do is to create a "loop-like" approach by using recursion.

The Code

function loopLike(int n){
 if (n > 100)
  return;
 else
  printf("Hello World\n");
 
 return loopLike(n+1);
}

loopLike(1);

The Algorithm

What we have done is called recursion. We did a loop-like approach by calling the function inside itself and limit it depending on our desired number of iteration.

Recursion is a programming technique that allows the programmer to express operations in terms of themselves. Basically it is a way where in one function calls itself or repeat the process.