AlgoDaily - Software interview prep made easy. Coding Interview Questions.

Max-heap trick for “Nth Smallest Number in a Stream” + edge cases

Challenges • Last reply from Sarah Chen at July 20, 2025 at 2:16PM UTC

For the AlgoDaily challenge “Nth Smallest Number in a Stream,” a clean approach is a size-N max-heap: Keep a max-heap of the N smallest numbers seen so far. On each new value x: If heap size < N, push it. Else if x < heap.max, pop max and push x. ...

1 post

Dollar Sign Deletion — simple stack vs O(1) two-pointer

Challenges • Last reply from Jun at July 4, 2025 at 2:16PM UTC

Anyone else find Dollar Sign Deletion easiest to reason about with two angles? Single string transform: iterate once, treat result as a stack . Push letters, pop on '$'. Compare-two-strings variant: walk from right to left with skip counters; no e...

1 post

'Implement ClearAllTimeouts' — what's the intended approach?

Challenges • Last reply from Ben at June 30, 2025 at 2:16PM UTC

Working on the Implement ClearAllTimeouts challenge and I’m unsure what’s expected. I tried two approaches: Brute force : const max = setTimeout => {}, 0); for clearTimeout; Issues: race-y, browser quirks with intervals, doesn’t work in Node wh...

1 post

Real-world strategies for zero-downtime doc DB schema changes

Challenges • Last reply from Sarah Chen at June 21, 2025 at 2:16PM UTC

The “Enhancing your Document-Oriented Database” lesson was a solid refresher on indexing and validation. Curious how folks here handle live schema evolution in production without outages. What’s worked well for me: - Add schemaVersion to every doc...

1 post

Majority Element - Python - Description Question

Challenges • Last reply from Sarah Chen at July 20, 2025 at 2:16PM UTC

the solution mentinons sorting ). instead we can use dictionary/hashmap sorting in O, n = number of elements searching for majority element O at worst case, m = number of keys of dictionary where m < n overall we are doing it in O, linear time `d...

4 posts

Two-Coloring Graph (Bipartite): quick checklist + a pitfall

Challenges • Last reply from Team AlgoDaily at July 20, 2025 at 2:16PM UTC

Working through AlgoDaily’s “The Two Coloring Graph Problem”? Here’s the pattern I reach for and a couple gotchas I keep seeing. Checklist: - Treat it as bipartite check. Use BFS/DFS to color 0/1. - Handle disconnected graphs: start from every unc...

2 posts

Sum until one digit

Challenges • Last reply from Jun at July 20, 2025 at 2:16PM UTC

Here's what I got for the solution function sumDigits { let n = num % 9; if { return 9; } else { return n; } } The challenge says expected time complexity to be O, but unless I'm missing something here. This is O isn't it?

4 posts

Sum Digits Until One

Challenges • Last reply from Team AlgoDaily at July 20, 2025 at 2:16PM UTC

Hi, guys! I have a question about "Sum Digits Until One" problem. When I run the code for all the test cases everything is perfect, but when I click 'RUN TESTS' button, it gives me an error: 4 ) ) ) Here is the code: def sumDigits: if n <...

10 posts

New challenge: Closures and Dependency Injection

Challenges • Last reply from Pat Kumar at July 12, 2025 at 2:16PM UTC

This week’s challenge is live: Closures and Dependency Injection. Prompt: - Implement makeCounter -> returns { inc, get }. - Use a closure to keep state. No globals or static module state. - inc increments the count and calls logger. - get returns...

2 posts

Is this website still going to be up?

Feedback • Last reply from Pat Kumar at July 12, 2025 at 2:16PM UTC

The website seems a little wonky and I checked the "newest additions" and its from January of 2024, a year ago. Is anyone still working on this website?

4 posts

c# converter

General • Last reply from Ben at July 12, 2025 at 2:16PM UTC

Are there any good javascript to c# converter, and vise versa, available to assist with completing the questions?

7 posts

How to rank the best essay writing services

General • Last reply from Team AlgoDaily at July 4, 2025 at 2:16PM UTC

Native English writers or ESL writers

5 posts

Lowest Common Ancestor - Python Question

Challenges • Last reply from Jun at July 4, 2025 at 2:16PM UTC

Test case tree2 is not valid. tree2 cannot represent a binary search tree since tree2 = Node tree2.left = Node tree2.right = Node violates the fact that left child should be smaller than root, but here left child is greater than root since 10 > ...

2 posts

Rights of Students at Law Students

General • Last reply from Sarah Chen at July 4, 2025 at 2:16PM UTC

Students have their rights at school that Constitution protects. Most schools are unaware of these rights, or most ignore them. Students should know about their rights before enrolling in any school. All the students are equal or fair. Rights are ...

4 posts

Error: Class, interface or enum expected

General • Last reply from Pat Kumar at July 4, 2025 at 2:16PM UTC

Hi, I'm trying to use the IDE in Java, but no matter what code I run, I get multiple errors saying "class, interface, or enum expected" despite the fact that the curly braces check out and that the primary function is within the Main method. Any t...

2 posts

What would you like from AlgoDaily?

Feedback • Last reply from Sarah Chen at June 30, 2025 at 2:16PM UTC

Hi guys, Jake here, founder of AlgoDaily. Thanks for checking the site out! I'm looking for feedback on what you guys would like to see. Is it more coding challenges? More career guides? A better way to reach out to professional developers? Let me...

7 posts

Crash Course: Introduction to Week 1, Part 1

General • Last reply from Ben at June 30, 2025 at 2:16PM UTC

General discussion thread for the week 1, part 1 of the crash course.

4 posts

What did you do in your first IT internship?

Career • Last reply from Jun at June 25, 2025 at 2:16PM UTC

Let's talk about how I got my first internship at the end of my third year. I started google a lot about how to get an internship as a first-year computer scientist. I understand that before applying for a position as a company internship, you nee...

6 posts

Count The Planes - Javascript Question

Challenges • Last reply from Jun at June 11, 2025 at 2:16PM UTC

Hey David, one way around it is, you can define planeMatrix1 in your code, and copy over one of the example test until they fix the issue. Link to problem: Count The Planes .

2 posts

Array Intersection: Solution doesn't run in IDE, but runs in my Terminal

Challenges • Last reply from Team AlgoDaily at June 11, 2025 at 2:16PM UTC

Can you tell me what's wrong here? My solution isn't running in the AlgoDaily IDE. The error says: "No Output." However, the seems to return the correct result when I run it in Python on my Terminal. Screenshot from AlgoDaily https://ibb.co/r4T39f...

5 posts

Fizz Buzz (Main Thread)

Challenges • Last reply from Myo at September 7, 2024 at 3:29PM UTC

This is the main discussion thread generated for Fizz Buzz .

14 posts

Valid Numeric String (Main Thread)

Challenges • Last reply from Jake from AlgoDaily at September 12, 2023 at 1:57AM UTC

This is the main discussion thread generated for Valid Numeric String .

1 post

four-sum (Main Thread)

Challenges • Last reply from Jake from AlgoDaily at August 28, 2023 at 12:27PM UTC

This is the main discussion thread generated for four-sum ).

1 post

How do I get my book edited?

General • Last reply from hudsonjade at May 19, 2023 at 9:29PM UTC

Hello everyone! I am writing a book that is going to be published next month but now that I have completed writing it I am not sure it is good enough to be published and worthy of making sales. I want help from any professional book editors UK wh...

2 posts

Reverse A String (Main Thread)

Challenges • Last reply from Devon Fazekas at May 16, 2023 at 5:08PM UTC

This is the main discussion thread generated for Reverse A String .

17 posts

How Can we Fast Our Internet.

General • Last reply from Thomas Delango at May 10, 2023 at 9:13AM UTC

Hey everyone, I'm in need of a good VPN for Brazil. I'm currently living here and facing some internet restrictions that are blocking me from accessing some of my favorite websites and content. I've been doing some research on Brazilian VPN servic...

3 posts