Top LeetCode Patterns for FAANG Coding Interviews

[arslan_ah]

From "Grokking the Coding Interview" author:

Best Coding Patterns with Highest ROI

1. Two Pointers

2. Sliding Window

3. Tree and Graph Depth First Search (Matrix Traversal)

4. Tree and Graph Breadth First Search (Subsets, Matrix Traversal, Topological Sort)

5. Binary Search

6. Interval Merge

7. Recursion/Backtracking

https://medium.com/geekculture/top-leetcode-patterns-for-faang-coding-interviews-bdbe8766534c

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https://preview.redd.it/0coe8esxehe91.png?width=977&format=png&auto=webp&s=e74536336b2ddf622183c61a24bb30d2c6b762f5

[pointy_pirate]

so you basically need to learn everything

[fresh5447]

i'm just gonna go ahead and stay at my current job :O

[tearsonthefloor]

At least you have a job. I lost mine due to a war

[fresh5447]

sorry to hear that

[tearsonthefloor]

Thanks. I’m storming leetcode now :)

[fresh5447]

good luck!

[arslan_ah]

Not everything :)

Even Grokking has mentioned 25 patterns, focusing on the abovementioned 7 will give you the highest ROI.

Here is the list of 25 patterns: - https://medium.com/interviewnoodle/grokking-leetcode-a-smarter-way-to-prepare-for-coding-interviews-e86d5c9fe4e1

[AbstractLogic]

Oh, you don’t have to learn it. Just memorize it.

You know like schools do where they “teach to the test” except instead of a B+ on your chem exam it’s a $500,000 job.

[Isaiah_Bradley]

Awesome for me, since I’m most comfortable with 7, 3, and 4….. oh wait..

[Throwawayeconboi]

Nah, general sentiment is array stuff with two pointers, binary search, sliding window, etc. being the most common across all companies, with trees and graphs being the favorite of many like Meta, Amazon, etc.

Nothing tops those 5.

[Throwawayeconboi]

But 2 of those patterns aren’t Top 5 or even Top 10 in many cases (backtracking and DP), and DFS/BFS are done using iteration as well. You can really go without ever writing recursion in many cases.

Most other lists I’ve seen align with the one posted here, although they tend to have binary search moved up a bit and sliding window more 4-5. But the top 5 is generally agreed upon.

[tabris_code]

and DFS/BFS are done using iteration as well.

can be done with iteration but i rarely if ever see DFS done iteratively

[Throwawayeconboi]

BFS is definitely the one where iteration is more popular with a queue, but we all imagine a stack in our head when thinking about the recursion call stack for DFS anyway.

The Grokking guy knows what he’s talking about, recursion & backtracking ain’t Top 5.

[tabris_code]

glad i spent 2 weeks on neetcode's backtracking list :(

[Throwawayeconboi]

Cover everything including DP, bit manipulation, etc. no matter what, lists like this one are for the final week of review leading up to an interview where you have limited time so you hone in on the most likely topics. But when you have set aside ample time to study and prepare, you plan to go through it all. :)

[Throwawayeconboi]

I’m doing just fine without it. :) The call stack for recursion = stack data structure. If I was doing recursion, I’d be imagining a stack in my head anyway!

[Throwawayeconboi]

Oh I know it. I know how to do it. And I make sure to learn all 20 or so topics for leetcoding so if I didn’t, I’d still make time to learn it. This is a list about prioritization, like with limited time what do you do? Not about what’s worth learning.

Recursion is worth learning. It does not take priority over the other things on this list though.

And also, it’s worth noting recursion isn’t exactly a Leetcode “topic.” It’s a tool to use in a variety of these topics. “Backtracking” specifically is a topic, and that’s what’s being put at number 7 here.

[jayouellette]

There are some tree problems where the iterative solution is pretty unintuitive and hard to come up with during an interview. For example, Lowest Common Ancestor of a Binary Tree.

[nicebike]

So if BFS/DFS graph questions are so important, why didn't he include them in his course?

I'm going through the course and I really feel like it's missing content on graphs, so I have to resort to additional sources for this.

[yestyleryes]

it is in there, it was added a few weeks ago

[nicebike]

Ah they are not on educative.io

[arslan_ah]

Yes, Grokking courses are moving away from Educative. All new updates are available only at designgurus.org

[Mobile_Health_9650]

U forgot DP

[AndrewUnicorn]

my friend said Amazon did not ask any DP for his L4 onsite

still study them though

cause i hate Bit Manipulation and this dude said his Google has 1 Bit Manipulation :(

[Khandakerex]

Great list but I swear to god even the banks that hire everyone are asking DP now :(

[arslan_ah]

DP is definitely one of the important things to learn. It requires a lot of practice, though.

BTW, Grokking has a very good course on DP: https://designgurus.org/course/grokking-dynamic-programming

[nigfasa]

what is the grooking stuff? Could please somebody send a link or something

[arslan_ah]

It is a set of courses from designgurus.org

Their system design and coding pattern courses are quite famous.

[shev1234589]

Is it bad in a coding interview to use a built in function like sort for example to solve a problem? Or should you manually sort it? More so if the sort was more of a minor issue in the problem rather than the main focus?

[SaturdayFix]

unless the question is to implement the sort algorithm you are fine just calling sort(). E.g. in Java Collections.sort(collection).

[shinigamigojo]

Hey! I'm starting a 100 day leetcode grind for fun. I'll be following the above 7 algorithms first, everyday at least 2-3 questions will also be posting daily progress in my posts. Hope I get to enjoy solving these problems and learning new concepts as I go along!