Python Interview with an interviewing.io engineer

Interview Summary

Problem type
Print k largest elements

Interview question

1. Given a integer as a input, replace all the ‘0’ with ‘5’ in the integer.
2. You are crossing a river using a series of rocks that stick out from the water. You can move across either one-rock at a time, or jump a rock in order to move ahead two rocks. Given there are 'r' rocks, how many distinct ways, 'n', can you cross?
3. Write an efficient program for printing k largest elements in an array. Largest elements are returned in order largest to smallest.

Interview Feedback

Feedback about Quantum Cheetah (the interviewee)
Advance this person to the next round?

Yes
How were their technical skills?
3/4
How was their problem solving ability?
4/4
What about their communication ability?
3/4

Great overall. As mentioned, pushing the pace a little is positive but take care it doesn't come a the expense of missing details in the questions that are being asked.

Feedback about The Incredible Croc (the interviewer)
Would you want to work with this person?
Yes

Interview Transcript

The Incredible Croc: Hello.
Quantum Cheetah: Hi there.
The Incredible Croc: Hi. How are you?
Quantum Cheetah: Doing well, how about you?
The Incredible Croc: Really well, thanks. Quick question to get started. Have you done an interview with interviewing.io before? Or is this your first time?
Quantum Cheetah: Yes, I have done two previously.
The Incredible Croc: Awesome. Cool. Okay, I guess you're already probably familiar with how the interface works in the editor, and so on. But if any questions, of course, let me know. And we'll figure it out together. What I'm going to do is just give you a quick overview of how I like to conduct these interviews and check that's okay with you, and then we'll kind of jump in from there. Cool. So I'll just start off with a few background questions get to know your experience and interests a little bit. It's an anonymous service so don't feel pressured or compelled to, like, share anything you're not comfortable with. But just give me a bit of a sense of, yeah, like where you've been and what you're interested in.

Interview Problem Details

1. Integer Replacement:
   Given a integer as input, replace all the ‘0’ with ‘5’ in the integer.

2. River Crossing:
   You are crossing a river using a series of rocks that stick out from the water. You can move across either one rock at a time or jump two rocks at a time. Given there are 'r' rocks, how many distinct ways can you cross?

3. k Largest Elements:
   Write an efficient program for printing k largest elements in an array. Largest elements are returned in order from largest to smallest.

Code Walkthrough

Example Solution for the River Crossing Problem:

• Base case: If r = 0, return 1 (one way to be still).
• Create two variables to track previous two ways to cross (A and B).
• Update A and B according to the number of rocks.
• For each rock, derive the number of ways to jump from two previous positions.

Technical Notes

• First problem focuses on technical skills and transferability of knowledge to the algorithm.
• Second problem revolves around identifying detail-oriented patterns in dynamic programming solutions.
• Final problem emphasizes understanding of sorting algorithms and efficient data handling.

Additional Technical Concepts Discussed

• Discussed the importance of edge cases and how to handle them effectively during problem-solving.
• Explored using heaps vs. sorting for efficient retrieval of k largest elements, understanding their respective runtimes and space complexities.
• Reviewed the nuances of handling negative numbers and zero cases effectively.