30-Day Data Structures and Algorithms Mastery Plan

Welcome to the 30-Day DSA Mastery Plan! This roadmap is designed to help you master Data Structures and Algorithms and prepare for coding interviews. Follow this daily plan to build a solid foundation and tackle challenging problems.

Week 1: Foundations and Basic Data Structures

Day 1: Arrays - Basics

• Topics to Cover:
  • Array basics, operations (insertion, deletion, searching)
• Practice Problems:
  • Easy: Two Sum
  • Medium: Maximum Subarray
  • Hard: Trapping Rain Water

Day 2: Arrays - Advanced Techniques

• Topics to Cover:
  • Two-pointer technique, sliding window technique
• Practice Problems:
  • Easy: Reverse a String
  • Medium: Longest Substring Without Repeating Characters
  • Hard: Minimum Window Substring

Day 3: Strings - Basics and Manipulations

• Topics to Cover:
  • String manipulation techniques
• Practice Problems:
  • Easy: Valid Anagram
  • Medium: Longest Palindromic Substring
  • Hard: Regular Expression Matching

Day 4: Linked Lists - Basics

• Topics to Cover:
  • Singly-linked list operations (insertion, deletion, reversal)
• Practice Problems:
  • Easy: Reverse a Linked List
  • Medium: Merge Two Sorted Lists
  • Hard: Reverse Nodes in k-Group

Day 5: Linked Lists - Advanced

• Topics to Cover:
  • Doubly linked list, circular linked list
• Practice Problems:
  • Easy: Remove Nth Node From End of List
  • Medium: Add Two Numbers (Linked List)
  • Hard: Merge k Sorted Lists

Day 6: Stacks - Basics

• Topics to Cover:
  • Stack operations (push, pop, top)
• Practice Problems:
  • Easy: Valid Parentheses
  • Medium: Implement Stack using Queues
  • Hard: Daily Temperatures

Day 7: Queues - Basics

• Topics to Cover:
  • Queue operations (enqueue, dequeue)
• Practice Problems:
  • Easy: Implement Queue using Stacks
  • Medium: Evaluate Reverse Polish Notation
  • Hard: Simplify Path

Week 2: Advanced Data Structures

Day 8: Trees - Basics

• Topics to Cover:
  • Binary Trees, Binary Search Trees (BST)
  • Tree traversal (preorder, inorder, postorder, level order)
• Practice Problems:
  • Easy: Invert Binary Tree
  • Medium: Validate Binary Search Tree
  • Hard: Binary Tree Maximum Path Sum

Day 9: Trees - Advanced

• Topics to Cover:
  • Advanced tree traversal and operations
• Practice Problems:
  • Easy: Symmetric Tree
  • Medium: Serialize and Deserialize Binary Tree
  • Hard: Recover Binary Search Tree

Day 10: Heaps - Basics

• Topics to Cover:
  • Binary heaps (min-heap, max-heap)
• Practice Problems:
  • Easy: Kth Largest Element in an Array
  • Medium: Top K Frequent Elements
  • Hard: Sliding Window Maximum

Day 11: Heaps - Advanced

• Topics to Cover:
  • Heap operations (insert, delete, extract-min/max)
• Practice Problems:
  • Easy: Find Median from Data Stream
  • Medium: Merge k Sorted Lists
  • Hard: Minimum Cost to Connect Sticks

Day 12: Hash Tables - Basics

• Topics to Cover:
  • Hashing concepts, hash functions, collision resolution
• Practice Problems:
  • Easy: Two Sum (using hash map)
  • Medium: Group Anagrams
  • Hard: Most Frequent Subtree Sum

Day 13: Hash Tables - Advanced

• Topics to Cover:
  • Advanced hash table operations and applications
• Practice Problems:
  • Easy: Subarray Sum Equals K
  • Medium: Longest Consecutive Sequence
  • Hard: Happy Number

Day 14: Review

• Activities:
  • Review and revisit challenging problems from Week 1 and Week 2

Week 3: Algorithms

Day 15: Sorting - Basics

• Topics to Cover:
  • Bubble sort, insertion sort
• Practice Problems:
  • Easy: Merge Intervals
  • Medium: Sort Colors
  • Hard: Largest Rectangle in Histogram

Day 16: Sorting - Advanced

• Topics to Cover:
  • Quick sort, merge sort
• Practice Problems:
  • Easy: Search Insert Position
  • Medium: Find Peak Element
  • Hard: Median of Two Sorted Arrays

Day 17: Searching - Basics

• Topics to Cover:
  • Binary search, linear search
• Practice Problems:
  • Easy: Binary Search
  • Medium: Search in Rotated Sorted Array
  • Hard: Find Minimum in Rotated Sorted Array

Day 18: Recursion - Basics

• Topics to Cover:
  • Basics of recursion, tail recursion
• Practice Problems:
  • Easy: Permutations
  • Medium: Combination Sum
  • Hard: N-Queens

Day 19: Recursion - Advanced

• Topics to Cover:
  • Backtracking (N-Queens, Sudoku solver)
• Practice Problems:
  • Easy: Subsets
  • Medium: Word Search
  • Hard: Sudoku Solver

Day 20: Divide and Conquer - Basics

• Topics to Cover:
  • Basic concept and techniques (merge sort, quick sort)
• Practice Problems:
  • Easy: Median of Two Sorted Arrays
  • Medium: Pow(x, n)
  • Hard: Maximum Subarray

Day 21: Review

• Activities:
  • Review and revisit challenging problems from Week 3

Week 4: Graphs and Dynamic Programming

Day 22: Graphs - Basics

• Topics to Cover:
  • Graph representations (adjacency list, adjacency matrix)
• Practice Problems:
  • Easy: Number of Islands
  • Medium: Clone Graph
  • Hard: Word Ladder II

Day 23: Graphs - Advanced

• Topics to Cover:
  • Graph traversal algorithms (DFS, BFS)
  • Shortest path algorithms (Dijkstra's, Bellman-Ford)
• Practice Problems:
  • Easy: Course Schedule
  • Medium: Minimum Height Trees
  • Hard: Traveling Salesman Problem

Day 24: Dynamic Programming - Basics

• Topics to Cover:
  • Basic concepts, memoization, tabulation
• Practice Problems:
  • Easy: Climbing Stairs
  • Medium: Longest Increasing Subsequence
  • Hard: Edit Distance

Day 25: Dynamic Programming - Advanced

• Topics to Cover:
  • Common dynamic programming problems (knapsack, longest common subsequence)
• Practice Problems:
  • Easy: Maximum Product Subarray
  • Medium: Partition Equal Subset Sum
  • Hard: Wildcard Matching

Day 26: Advanced Topics - Basics

• Topics to Cover:
  • Bit manipulation, greedy algorithms
• Practice Problems:
  • Easy: Single Number
  • Medium: Decode Ways
  • Hard: N-Queens II

Day 27: Advanced Topics - Advanced

• Topics to Cover:
  • Miscellaneous problems (trie, segment tree, disjoint set)
• Practice Problems:
  • Easy: Implement Trie (Prefix Tree)
  • Medium: Segment Tree (Range Sum Query)
  • Hard: Minimum Spanning Tree

Day 28: Review

• Activities:
  • Review and revisit challenging problems from Week 4

Week 5: Review and Mock Interviews

Day 29: Review and Weakness Analysis

• Activities:
  • Review topics and problems you found challenging
  • Revisit and practice weak areas

Day 30: Mock Interviews and Practice

• Activities:
  • Conduct mock interviews with a friend or use online platforms
  • Focus on communication and explaining your thought process

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Additional Resources

• LeetCode
• GeeksforGeeks
• HackerRank
• CodeSignal

Happy coding and good luck with your interview preparation!

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🍴 How to Fork This Repository

If you'd like to use this repository on your local machine, follow these steps to fork it:

1. Fork the Repository:

   • Go to the GitHub page of the repository you want to fork.
   • Click the "Fork" button at the top right of the page.

2. Clone Your Forked Repository:

   • After forking, you will have a copy of the repository in your GitHub account.
   • Copy the URL of your forked repository. You can find this by navigating to your forked repository on GitHub and clicking the green "Code" button, then copying the URL provided.

   Example URL: https://github.com/YOUR_USERNAME/YOUR_FORK.git

   • Open your terminal and clone your forked repository using the following command:

     git clone https://github.com/YOUR_USERNAME/YOUR_FORK.git

3. Navigate into the Project Directory:

   • Change into the directory of your cloned repository:

     cd YOUR_FORK

4. Add the Original Repository as a Remote:

   • It’s a good practice to add the original repository as a remote to keep your fork up-to-date with the latest changes.

     git remote add upstream https://github.com/ORIGINAL_OWNER/ORIGINAL_REPOSITORY.git

     Replace ORIGINAL_OWNER and ORIGINAL_REPOSITORY with the original repository's owner and name.

5. Pull Latest Changes from the Original Repository:

   • Before making changes, ensure you have the latest updates from the original repository:

     git fetch upstream
     git checkout main
     git merge upstream/main

6. Make Changes and Commit:

   • Create a new branch for your changes:

     git checkout -b your-branch-name

   • Make your changes and commit them:

     git add .
     git commit -m "Description of your changes"

7. Push Your Changes:

   • Push your changes to your forked repository:

     git push origin your-branch-name

8. Create a Pull Request:

   • Go to your forked repository on GitHub.
   • Click the "Compare & pull request" button.
   • Provide a description of your changes and submit the pull request to the original repository.

Example Commands

Here's a summary of the commands you will use:

# Clone your forked repository
git clone https://github.com/YOUR_USERNAME/YOUR_FORK.git

# Navigate into the project directory
cd YOUR_FORK

# Add the original repository as a remote
git remote add upstream https://github.com/ORIGINAL_OWNER/ORIGINAL_REPOSITORY.git

# Fetch and merge changes from the original repository
git fetch upstream
git checkout main
git merge upstream/main

# Create a new branch, make changes, and commit
git checkout -b your-branch-name
git add .
git commit -m "Description of your changes"

# Push changes to your fork and create a pull request
git push origin your-branch-name

🚨 Warnings and Cautions

• Be Respectful:

  • Follow the code of conduct and be respectful of other contributors.

• Test Your Changes:

  • Ensure your changes are tested and do not break existing functionality.

• Keep Your Fork Updated:

  • Regularly pull changes from the original repository to keep your fork up-to-date.