📘 Good to Know ⭐ Patterns 📌 ArrayList 🗺️ HashMap 🔄 Two Pointers 📚 Stack 🔗 LinkedList
P
Pavan Prakash
SDE @ Prodhee Tech · Dhee Coding Lab
🏆 LeetCode & HackerRank Expert 🚀 Cracked TCS Codevita ⚡ Contest Expert
2000+
Students Mentored
1500+
DSA Questions Solved
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✅ Use Your Own Logic

Don't copy variables or logic. Understand concepts & create your own approach.

🎯 Extract Concepts

Focus on core ideas, implement them your own way — not just the solution.

🤔 Understand the "Why"

Analyze the necessity of each part to grasp deeper algorithmic thinking.

🚀 Prepare for Advanced

Solid foundation here makes Pro Max-level problems easy to adapt to.

📌 Course Completion PathRookie ModulePro Max Series

Once you complete this, you are king of your own territory in DSA.

📝 Create revision notes  ·  Complete all videos + notes (even if you know the solution)  ·  Give contests on LeetCode & CodeChef to keep hustling!

📖

Good to Know

☕ Java
Crash Course + Collections CheatSheet
🔥 Class Recording 📄 CheatSheet
🐍 Python
Core DSA + Collections CheatSheet
🔥 Class Recording 📄 CheatSheet

Pattern Programming

4 Sessions
SessionContentResourcesImportancePractice
Pattern-1 Basic patterns — squares, triangles, stars Core Click Here to Practice
Pattern-2 Number patterns + pyramid variations Core Click Here to Practice
Pattern-3 Diamond, hourglass & complex patterns Medium Click Here to Practice
Pattern-4 Finale All pattern types — full revision + notes Critical Click Here to Practice
📌

ArrayList (Java) / List (Python)

9 Sessions
SessionContentResourcesImportancePractice
AL-01 Intro Part 1 — Array basics & methods Core
AL-02 Intro Part 2 — Iteration & in-place ops Core
AL-03 Prefix Sum Array High Running Sum Simple Array Sum
AL-04 Nested List + HackerRank challenges Medium Mini-Max Sum Diagonal Diff
AL-05 Brute Force & Subarrays Critical Click Here to Practice
AL-06 Merge Strings Alternately Medium Click Here to Practice
AL-07 Product of Array Except Self Critical Click Here to Practice
AL-08 Increasing Triplet Subsequence High Click Here to Practice
AL-09 Can Place Flowers Medium Click Here to Practice
🗺️

HashMap (Java) / Dictionary (Python)

14 Sessions
SessionContentResourcesImportancePractice
HM-01 Intro + Methods Core
HM-02 Frequency HashMap — Java & Python Critical Valid Anagram
HM-03 Identify Duplicates High Contains Duplicate All Duplicates
HM-04 HashMap + Prefix Sum (SubArray Sum = k) Critical
HM-05 Remove Duplicates High All Duplicates
HM-06 Strings Frequency HashMap High First Unique Char
HM-07 Kadane's Algorithm 🔥 Critical Click Here to Practice
HM-08 Longest SubArray (same begin/end) High Click Here to Practice
HM-09 Time Complexity Critical
HM-10 Two Sum O(n) Optimisation Critical Two Sum
HM-11 Subarray XOR == 0 High
HM-12 Isomorphic Strings Medium Click Here to Practice
HM-13 Best Time to Buy and Sell Stocks Critical Click Here to Practice
HM-14 HashMap Module · Group Anagrams · Happy Number · k Unique High Group Anagrams
🔄

Two Pointers

5 Sessions
SessionContentResourcesImportancePractice
TP-01 Intro + Two Pointers Template Core
TP-02 3Sum + Intersection of 2 Arrays Critical Click Here to Practice
TP-03 4Sum High Click Here to Practice
TP-04 Reverse Vowels of a String Medium Click Here to Practice
TP-05 Is Subsequence Medium Click Here to Practice
📚

Stack

2 Sessions
SessionContentResourcesImportancePractice
ST-01 Introduction to Stack Core
ST-02 Valid Parentheses [LeetCode] Critical Click Here to Practice
🔗

LinkedList

7 Sessions
SessionContentResourcesImportancePractice
LL-01 Intro to LinkedList Core
LL-02 Linked List Cycle Critical Click Here to Practice
LL-03 Sort List High Click Here to Practice
LL-04 Middle of the Linked List High Click Here to Practice
LL-05 Odd Even Linked List Medium Click Here to Practice
LL-06 Remove LinkedList Elements High Click Here to Practice
LL-07 Delete the Middle Node of a Linked List High Click Here to Practice