Easy Recursion Question 67 of 224

How do you print numbers from 1 to n using recursion?

DSA interview set · Speak this in 60–90 seconds · Faridabad & Delhi NCR

StackLIFOlast in, first out

QueueFIFOfirst in, first out

Recurse on n-1 first, then print n, so the prints happen on the way back

Why interviewers care about Recursion:

This is a process

question about Recursion.

Panels listen for order,

trade-offs, and what you would actually do on a DSA project - not buzzwords.

Stay structured

Name the idea, why it exists, then one short example.

Close cleanly

End with when you use it and one common pitfall.

Before you speak the answer, walk the interviewer through these steps:

1
Recurse on n-1 first,
then print n, so the prints happen on the way back
2
the base is n
== 0.
3
Time is O(n) and
stack space is O(n).
4
Printing before the recursive
call would print n down to 1, which is a common mix-up to mention.
5
Common mistake
What juniors usually get wrong.
6
Close
When you pick this over the alternative.

Here's a short line you can speak, broken into clear beats:

Say this line

“Time is O(n) and stack space is O(n).”

Break into beats

TimeisOnandstack

Speaking order

2987408337471632900

Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.

Recurse on n-1 first, then print n, so the prints happen on the way back the base is n == 0.