initial plan

When preparing for DSA-related interviews, it’s helpful to focus on problems that are commonly encountered. Here’s a categorization of common problems, including the more frequently seen ones like array and string problems, and the less common ones like dynamic programming.

Common DSA Problems for Interviews

1. Arrays and Strings

• Arrays:

  • Two Sum
  • Maximum Subarray
  • Merge Intervals
  • Product of Array Except Self
  • Rotate Array
  • Best Time to Buy and Sell Stock
  • Find Minimum in Rotated Sorted Array
  • Contains Duplicate
  • Maximum Product Subarray

• Strings:

  • Longest Substring Without Repeating Characters
  • Valid Anagram
  • Palindromic Substrings
  • Longest Palindromic Substring
  • Group Anagrams
  • Minimum Window Substring
  • Implement strStr() (Substring Search)

2. Linked Lists

• Reverse Linked List
• Merge Two Sorted Lists
• Linked List Cycle
• Remove Nth Node From End of List
• Intersection of Two Linked Lists

3. Trees and Graphs

• Trees:

  • Binary Tree Inorder Traversal
  • Validate Binary Search Tree
  • Maximum Depth of Binary Tree
  • Lowest Common Ancestor of a Binary Search Tree
  • Serialize and Deserialize Binary Tree

• Graphs:

  • Clone Graph
  • Course Schedule
  • Number of Islands
  • Graph Valid Tree
  • Word Ladder

4. Dynamic Programming (Less Common but Important)

• Basic Problems:

  • Climbing Stairs
  • House Robber
  • House Robber II
  • Coin Change
  • Longest Increasing Subsequence

• Advanced Problems:

  • Word Break
  • Combination Sum IV
  • Edit Distance
  • Interleaving String

5. Sorting and Searching

• Sorting Algorithms:

  • Quick Sort
  • Merge Sort
  • Heap Sort
  • Bubble Sort
  • Selection Sort
  • Insertion Sort

• Searching:

  • Binary Search
  • Search in Rotated Sorted Array
  • Find Peak Element

6. Backtracking

• Permutations
• Subsets
• Combination Sum
• Palindrome Partitioning
• N-Queens

7. Miscellaneous

• Stack and Queue:

  • Valid Parentheses
  • Implement Stack using Queues
  • Implement Queue using Stacks
  • Min Stack
  • Sliding Window Maximum

• Bit Manipulation:

  • Single Number
  • Number of 1 Bits
  • Reverse Bits
  • Power of Two

Organizational Method for Notes

1. Create a Folder Structure:

   • Leetcode DSA Problems
     • Arrays
     • Strings
     • Linked Lists
     • Trees
     • Graphs
     • Dynamic Programming
     • Sorting and Searching
     • Backtracking
     • Miscellaneous

2. Note-Taking Format:

   • Problem Title:
   • Problem Description:
   • Approach:
     • Brute Force Approach
     • Optimized Approach
     • Code
   • Complexity Analysis:
     • Time Complexity
     • Space Complexity
   • Edge Cases:
   • Personal Notes:
     • Insights, mistakes, things to remember

3. Tracking Solved Problems:

   • Create a master note or a spreadsheet that lists all the problems you’ve solved.
   • Include columns for the problem title, link to the Leetcode problem, date solved, difficulty level, and a link to your detailed note on the problem.

4. Linking Notes:

   • Use the backlinking feature of Obsidian to link related notes. For instance, link a note on “Longest Substring Without Repeating Characters” to notes on other string problems.
   • OR use tags for strings etc - similar to leetcode site

By organizing your notes this way, you’ll have a comprehensive and easily navigable record of your DSA problem-solving journey, which can be invaluable for interview preparation.