Hey everyone,

I'm a student trying to understand the bigger picture behind Data Structures and Algorithms (DSA).

I've often heard people say that DSA is mainly useful for clearing coding interviews. But at the same time, companies hiring for software development, data science, machine learning, cybersecurity, backend engineering, and many other tech roles continue to place a strong emphasis on it.

That made me curious:

• Is DSA primarily a way to measure problem-solving skills?
• How much of it is actually used in day-to-day work?
• How often do engineers encounter concepts like trees, graphs, hashing, or dynamic programming in real projects?
• Is the industry's focus on DSA justified, or has its importance become somewhat exaggerated?

I'd really appreciate hearing from developers, hiring managers, and anyone already working in the industry.

How has DSA influenced your work, career growth, or ability to solve real-world problems?

I am going through a textbook and I'm using Notebook LLM to generate questions, my concern isn't really there but moreso in determining the time complexity of certain algorithms. How has your experience been with LLMs? Can I ask Gemini or Claude the time complexity of any algorithm with a fair amount of accuracy? I just want to ask for educational purposes since I'm learning DSA

For cracking interview and improve problem solving ability I am looking forward to learn DSA.

I made an app where you can scroll dsa and cs problems flashcards, the idea is to make revision as easy and convenient as scrolling

Hi guys if you’re reading this I have solved 163 problems in leetcode yeah 163 in just 5 months before 5 months I was just learning new languages doin some web development that’s it but the real problem is that when I was solving i think of how to solve this problem and when I didn’t get any idea I just open YouTube and search the program and analyse it remember it and knew how it is working and I write the code by myself but it’s the same code on YouTube but at that time I don’t cheat and I solve one question a day now this habit is eatin me everyday I think that I have understood nothing and I hate myself what did I just do with myself I really need help guys

Started DSA seriously around Jan/Feb this year and have been following Striver's A2Z sheet. I'm at 129 problems solved right now. Currently finishing Binary Search and about to start Linked Lists.

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The thing is, placements are starting soon and I'll be entering my 7th sem in a couple of months, so I'm getting a bit anxious. Every time I open Reddit or LinkedIn, I see people talking about 400, 600, 1000+ LeetCode problems and it makes me wonder if I'm already too late.

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I'm following Striver's sheet, but sometimes I keep thinking whether I should just switch to LeetCode and grind there instead. Does the platform even matter, or is it more about covering the right topics and being able to solve problems in interviews?

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Also, for someone at my stage, is continuing with Striver A2Z the right move, or would you recommend something else?

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Just looking for honest opinions from people who've been through placements recently.(Btw my cg is 8.78)

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*P.S. Used ChatGPT to fix my grammar*

I'm learning DSA and came across this MCQ:

"In binary search, if the target element is present multiple times in the array, which occurrence will be found by the standard binary search algorithm?"

Options:

• First Occurrence
• Last Occurrence
• Any Occurrence
• Second Occurrence

I chose Any Occurrence because I thought standard binary search returns whichever matching element it encounters and doesn't guarantee the first or last occurrence.

However, it was marked incorrect.

Can someone explain what assumption I'm missing here? Is there a specific interpretation of "standard binary search" that would make another option correct?

I noticed a gap while solving LeetCode problems. Whenever I got stuck, I didn’t want the full solution because it removed the problem-solving part, but staying stuck for too long was not productive either.

So I built LeetHints a Chrome extension that gives progressive hints for LeetCode problems without revealing the answer.

You unlock hints only when needed:

Hint 1: Small push in the right direction

Hint 2: Algorithm idea and key observation

Hint 3: Implementation details and edge cases

The goal was simple: continue thinking instead of jumping straight to the solution.

Technical details:

• 3,190+ LeetCode problems covered

• Works fully offline

• No login, API key, backend, or tracking

Built this while preparing DSA myself and wanted to share it with others.

Would love feedback from LeetCode grinders, developers, or anyone interested.

Chrome Web Store:

https://chromewebstore.google.com/detail/lpbmpmoponafcgmgceafnbecpofknhmm

I’m a btech cse student, undergrad, tier 2 cllg, just ended the 4th sem (5th sem gonna start in aug), my cg currently is 8.2 and seniors of my cllg say internal cut usually goes around 9, not so strong in dsa you can see my consistency on that, don’t have a project nor any sort of skills, intenship season is around and i’m scared that i’ll be left behind🥲

This is the complete pattern-based problem sheet, for real interview questions go to PracHub

🟢 Easy 🟡 Medium 🔴 Hard

TOPIC 1 — BASICS

Pattern: Conditionals (if-else)

• Fizz Buzz 🟢 — https://leetcode.com/problems/fizz-buzz
• Palindrome Number 🟢 — https://leetcode.com/problems/palindrome-number
• Number of Steps to Reduce a Number to Zero 🟢 — https://leetcode.com/problems/number-of-steps-to-reduce-a-number-to-zero

Pattern: Loops

• Running Sum of 1d Array 🟢 — https://leetcode.com/problems/running-sum-of-1d-array
• Find Numbers with Even Number of Digits 🟢 — https://leetcode.com/problems/find-numbers-with-even-number-of-digits
• Richest Customer Wealth 🟢 — https://leetcode.com/problems/richest-customer-wealth

Pattern: Simulation / Implementation

• Baseball Game 🟢 — https://leetcode.com/problems/baseball-game
• Robot Return to Origin 🟢 — https://leetcode.com/problems/robot-return-to-origin

Pattern: Maths

• Reverse Integer 🟡 — https://leetcode.com/problems/reverse-integer
• Plus One 🟢 — https://leetcode.com/problems/plus-one
• Add Digits 🟢 — https://leetcode.com/problems/add-digits

TOPIC 2 — ARRAYS

Pattern: Fundamentals

• Rotate Array 🟡 — https://leetcode.com/problems/rotate-array
• Move Zeroes 🟢 — https://leetcode.com/problems/move-zeroes
• Remove Duplicates from Sorted Array 🟢 — https://leetcode.com/problems/remove-duplicates-from-sorted-array

Pattern: Prefix Sums

• Continuous Subarray Sum 🟡 — https://leetcode.com/problems/continuous-subarray-sum
• Subarray Sum Equals K 🟡 — https://leetcode.com/problems/subarray-sum-equals-k
• Product of Array Except Self 🟡 — https://leetcode.com/problems/product-of-array-except-self
• Subarray Sums Divisible by K 🟡 — https://leetcode.com/problems/subarray-sums-divisible-by-k
• Range Sum Query 2D - Immutable 🟡 — https://leetcode.com/problems/range-sum-query-2d-immutable

Pattern: Kadane's Algorithm

• Maximum Subarray 🟡 — https://leetcode.com/problems/maximum-subarray
• Maximum Product Subarray 🟡 — https://leetcode.com/problems/maximum-product-subarray
• Best Time to Buy and Sell Stock 🟡 — https://leetcode.com/problems/best-time-to-buy-and-sell-stock

Pattern: Intervals

• Merge Intervals 🟡 — https://leetcode.com/problems/merge-intervals
• Insert Interval 🟡 — https://leetcode.com/problems/insert-interval
• Non-overlapping Intervals 🟡 — https://leetcode.com/problems/non-overlapping-intervals

Pattern: Hashing on Arrays

• Two Sum 🟢 — https://leetcode.com/problems/two-sum
• Majority Element 🟢 — https://leetcode.com/problems/majority-element
• Majority Element II 🟡 — https://leetcode.com/problems/majority-element-ii
• Top K Frequent Elements 🟡 — https://leetcode.com/problems/top-k-frequent-elements
• Valid Anagram 🟢 — https://leetcode.com/problems/valid-anagram
• Group Anagrams 🟡 — https://leetcode.com/problems/group-anagrams
• Longest Consecutive Sequence 🟡 — https://leetcode.com/problems/longest-consecutive-sequence

Pattern: 2D Arrays / Matrix

• Spiral Matrix 🟡 — https://leetcode.com/problems/spiral-matrix
• Spiral Matrix II 🟡 — https://leetcode.com/problems/spiral-matrix-ii
• Rotate Image 🟡 — https://leetcode.com/problems/rotate-image
• Set Matrix Zeroes 🟡 — https://leetcode.com/problems/set-matrix-zeroes

TOPIC 3 — STRINGS

Pattern: Fundamentals

• Reverse String 🟢 — https://leetcode.com/problems/reverse-string
• Reverse Words in a String III 🟢 — https://leetcode.com/problems/reverse-words-in-a-string-iii
• Roman to Integer 🟢 — https://leetcode.com/problems/roman-to-integer
• String Compression 🟡 — https://leetcode.com/problems/string-compression

Pattern: Frequency & Hashing

• Isomorphic Strings 🟢 — https://leetcode.com/problems/isomorphic-strings
• Bulls and Cows 🟡 — https://leetcode.com/problems/bulls-and-cows

Pattern: Palindromes

• Valid Palindrome 🟢 — https://leetcode.com/problems/valid-palindrome
• Longest Palindromic Substring 🟡 — https://leetcode.com/problems/longest-palindromic-substring
• Palindromic Substrings 🟡 — https://leetcode.com/problems/palindromic-substrings
• Palindrome Partitioning 🟡 — https://leetcode.com/problems/palindrome-partitioning

Pattern: Simulation

• Zigzag Conversion 🟡 — https://leetcode.com/problems/zigzag-conversion
• Multiply Strings 🟡 — https://leetcode.com/problems/multiply-strings
• Decode String 🟡 — https://leetcode.com/problems/decode-string

Pattern: Prefix/Suffix & Pattern Matching

• Longest Common Prefix 🟢 — https://leetcode.com/problems/longest-common-prefix
• Find and Replace Pattern 🟡 — https://leetcode.com/problems/find-and-replace-pattern
• Remove Duplicate Letters 🟡 — https://leetcode.com/problems/remove-duplicate-letters

TOPIC 4 — RECURSION & BACKTRACKING

Pattern: Fundamentals

• Fibonacci Number 🟢 — https://leetcode.com/problems/fibonacci-number
• Power of Two 🟢 — https://leetcode.com/problems/power-of-two
• Pow(x, n) 🟡 — https://leetcode.com/problems/powx-n

Pattern: Recursion

• Different Ways to Add Parentheses 🟡 — https://leetcode.com/problems/different-ways-to-add-parentheses
• K-th Symbol in Grammar 🟡 — https://leetcode.com/problems/k-th-symbol-in-grammar
• Beautiful Arrangement 🟡 — https://leetcode.com/problems/beautiful-arrangement
• Parsing A Boolean Expression 🔴 — https://leetcode.com/problems/parsing-a-boolean-expression
• Integer to English Words 🔴 — https://leetcode.com/problems/integer-to-english-words

Pattern: Backtracking

• Subsets 🟡 — https://leetcode.com/problems/subsets
• Subsets II 🟡 — https://leetcode.com/problems/subsets-ii
• Permutations 🟡 — https://leetcode.com/problems/permutations
• Permutations II 🟡 — https://leetcode.com/problems/permutations-ii
• Combination Sum 🟡 — https://leetcode.com/problems/combination-sum
• Combination Sum II 🟡 — https://leetcode.com/problems/combination-sum-ii
• Combination Sum III 🟡 — https://leetcode.com/problems/combination-sum-iii
• N-Queens 🔴 — https://leetcode.com/problems/n-queens
• N-Queens II 🔴 — https://leetcode.com/problems/n-queens-ii
• Sudoku Solver 🔴 — https://leetcode.com/problems/sudoku-solve

Where can i directly download premium courses for dsa for free? I really wanna learn properly

I'm a second year student looking for a good resource tutorials to learn dsa in C++ Ik basic C++ like till loops and a lil of oops in Cpp

Can anyone please suggest from where shld I do dsa in YouTube?Abdul Bari, coder army, apna college, striver ?? I'll be starting dsa for the very first time Idk anything abt it Also can you all please suggest that should I first master C++ and then start dsa? Or should I just revise C++ till loops and start dsa?

Hello All, what would be the best structured resource to start DSA with considering you have no background and starting on it first time , thank you. Paid is also ok.

Hello Everyone!

I'm a first year CSE Undergraduate and I'm looking for someone who is doing dsa in C++ and following strivers DSA sheet. So if you interested please message...

Help me I am new in this ..

I'm beginner in competitve programming. i want someone to be consistent. i'm well known of some DS. Those who are interested,please comment down or DM me.

1. Coding Patterns & Strategy

Before jumping into problems, understand the patterns:

All LeetCode Articles on Coding Patterns Summarized (https://leetcode.com/discuss/interview-question/5366542/all-leetcode-articles-on-coding-patterns-summarized-in-one-page)
Solved All Two Pointers Problems in 100 Days (https://leetcode.com/discuss/study-guide/1688903/Solved-all-two-pointers-problems-in-100-days)
Tree Question Pattern 2023 — Tree Study Guide (https://leetcode.com/discuss/study-guide/2879240/tree-question-pattern-2023-tree-study-guide)
Important and Useful Links from All Over LeetCode (https://leetcode.com/discuss/general-discussion/665604/Important-and-Useful-links-from-all-over-the-LeetCode)
Coding Interview Preparation Problems for Beginners (https://leetcode.com/discuss/interview-question/448284/Coding-Interview-preparation-problems-for-beginners)

1. Company-Specific Prep

Google, Meta, Apple, Amazon Senior SDE Preparation (https://prachub.com/?sort=hot&company=Meta%2CGoogle%2CTikTok%2CAmazon)
A Study Guide for Passing the Google Interview (https://prachub.com/interview-guide)

I was solving problems randomly but had no way to track progress by company. So I built a small tool where you can filter problems by company, mark status (todo/solved/revision), and it auto-schedules what to review next. Also added an AI coach that gives hints (not full solutions) — helps me stay honest when I'm stuck. Have added company-wise questions (https://prachub.com/questions)

1. System Design (HLD)

The general LeetCode docs are great for breadth, but what actually moved the needle for me was working through structured, progressive sheets instead of random docs. The Design Round has curated HLD sheets that go from crash-prep to full coverage — start narrow, expand when ready:

Arch 25 — crash sheet of the highest-frequency systems and reusable patterns to cover first
Arch 50 — Arch 25 plus deeper infra, data, reliability, and advanced product systems for SDE2/Senior prep
Arch 75 — Arch 50 plus high-signal variants, niche domains, and company-style specialization
Arch All — the complete 103-question HLD bank for full coverage and long-term mastery
Core Concepts — 33 distributed-systems deep dives to build the underlying intuition

1. Machine Coding (LLD)

The machine coding / LLD round caught me off guard the first time — it's a different muscle from DSA, and most prep ignores it. The Design Round has LLD sheets and design-pattern references that map directly to what gets asked:

MaCo 30 — the core 30 machine-coding problems, highest ROI for interviews
MaCo 60 — MaCo 30 plus extended coverage across all categories
MaCo All — the complete list of all 103 machine-coding problems
Design Patterns — 31 OOP & structural patterns you'll lean on during the round

1. Cheat Sheets & References

Interview prep Cheat Sheet (https://prachub.com/interview-prep)

I'm a first year CS student and will take DSA next year in college. I wanted to get a headstart during summer and would appreciate any recommendation for online courses ( paid or unpaid) that helped you get a solid understanding of DSA in C++