Data Structures & Algorithms

Interview Prep And Revision

Final Revision & Next Steps

Eleven modules, roughly fifty chapters, starting from "what does Big O even mean" and ending with narrating a graph-cycle-detection solution like an interview c

JrCodex·5 min read

Jr Codex DSA Notes

Level: Advanced Prerequisites: Chapter 3 Time to complete: ~20 minutes


Table of Contents

  1. You've Completed the DSA Curriculum
  2. Full Curriculum Recap
  3. Self-Assessment Checklist
  4. If Something Felt Shaky
  5. What to Do Next
  6. Where This Curriculum Leads

1. You've Completed the DSA Curriculum

Eleven modules, roughly fifty chapters, starting from "what does Big O even mean" and ending with narrating a graph-cycle-detection solution like an interview candidate. This chapter is a deliberate step back — a recap, an honest self-check, and a pointer to what comes after.


2. Full Curriculum Recap

ModuleOne-Line Recap
1. Complexity AnalysisBig O measures how runtime/memory scale, not raw speed — the vocabulary for everything after it
2. Arrays & StringsTwo-pointer and sliding window turn many O(n²) brute forces into O(n)
3. Searching & SortingBinary search needs sorted data; merge/quick sort achieve O(n log n), the best general comparison-sort bound
4. Recursion & BacktrackingRecursion needs a base case and a shrinking input; backtracking adds "choose, recurse, un-choose" to explore combinations
5. Stacks & QueuesLIFO (stack) and FIFO (queue) are the right tool whenever order-of-processing itself is the constraint
6. Linked ListsPointer rewiring (not array shifting) is what makes insert/delete O(1) once you're at the right node
7. Trees & HeapsTrees generalize linked lists to branching structures; heaps give O(log n) access to the min/max element
8. HashingHash maps/sets trade O(n) space for O(1) average-case lookups — the single highest-leverage trick in this curriculum
9. GraphsBFS for shortest paths in unweighted graphs, DFS for exploring/reachability — both O(V + E)
10. Dynamic Programming & GreedyDP memoizes overlapping subproblems; greedy is faster but only correct when an early choice never forecloses a better later one
11. Interview Prep & RevisionRecognizing which of the above ten toolkits a new problem needs, and narrating your reasoning while you apply it

3. Self-Assessment Checklist

For each item, ask yourself: "Could I implement this from scratch, correctly, in under 10 minutes, without looking anything up?" If not, that module is worth a second pass before you consider yourself interview-ready.

  • Explain why an algorithm is O(n log n) rather than O(n²), from the code alone (Module 1)
  • Solve a "longest substring/subarray matching a condition" problem with sliding window (Module 2)
  • Implement binary search and merge sort without referencing notes (Module 3)
  • Write a backtracking solution for subsets or permutations (Module 4)
  • Implement a valid-parentheses checker using a stack, and a level-order traversal using a queue (Module 5)
  • Reverse a singly linked list and detect a cycle with fast/slow pointers (Module 6)
  • Write all three tree traversals and a min-heap-based "kth largest" solution (Module 7)
  • Solve Two Sum with a hash map in one pass (Module 8)
  • Implement BFS and DFS on an adjacency list, and explain when to use each (Module 9)
  • Convert a naive exponential recursive solution into a memoized or tabulated O(n)/O(n²) one (Module 10)
  • Given a brand-new problem, name the likely pattern within a minute using Chapter 1's cheat sheet (Module 11)

4. If Something Felt Shaky

Don't treat any unchecked box as a failure — treat it as a targeted to-do list. Go back to that specific module (not the whole curriculum), re-read the chapter, and re-implement its core example without looking at the solution first. DSA retention comes from repetition of implementation, not re-reading — this was true from Module 1's study-tips chapter onward, and it's still true here at the end.


5. What to Do Next

  • Keep practicing on a problem platform (LeetCode, HackerRank, or similar) — apply Chapter 1's pattern-recognition table to every new problem before looking at hints.
  • Time yourself — once the patterns feel familiar, practice under a 25-30 minute constraint per problem to simulate real interview pressure.
  • Revisit Module 11 before any interview — Chapter 1's cheat sheet and Chapter 3's four-step narration shape are meant to be refreshed right before you need them, not just read once.
  • Pair this with real projects — DSA patterns (hashing for caching, graphs for dependency resolution, heaps for scheduling) show up constantly in production code, not just interviews.

6. Where This Curriculum Leads

DSA is a supporting pillar for the rest of the Jr Codex curriculum — the algorithmic thinking built here (especially recursion, complexity tradeoffs, and graph traversal) shows up again once you're reasoning about model training loops, search algorithms in AI, and production ML systems.

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