Progress · 0/6 phases
🧩 🧩 90-Day DSA Roadmap — Beginner to Advanced
3 min read · Notion
From array basics to advanced dynamic programming and graph algorithms. A structured, daily-practice roadmap with patterns, problems, code templates, and the exact thinking process interviewers expect.
How to use this template
- Work phases in order — each pattern builds on the previous
- Every day: study the pattern + solve 3 problems at minimum (1 easy, 1 medium, 1 hard or 2 medium)
- Understand the pattern, not just the solution. Ask: when do I reach for this?
- Use the Daily Tracker to log problems, time taken, and one key insight
- Mark a problem Done only when you can solve it without hints in under 20 minutes
The rule: if you solved a problem by looking at the solution, it counts as Studied, not Solved. Come back in 3 days and solve it from scratch.
Roadmap at a glance
| Phase | Days | Focus | Core Patterns |
|---|---|---|---|
| Phase 1 — Foundations | 1–15 | Arrays, Strings, Two Pointers, Sliding Window | Prefix sum, Two pointer, Sliding window |
| Phase 2 — Core Data Structures | 16–35 | Linked Lists, Stacks, Queues, Hashing, Trees | Fast/slow pointer, Monotonic stack, BFS/DFS |
| Phase 3 — Advanced Data Structures | 36–55 | Heaps, Graphs, Tries, Union-Find | Top-K, Shortest path, Trie prefix |
| Phase 4 — Core Algorithms | 56–75 | Recursion, Backtracking, DP, Greedy, Divide & Conquer | Memoization, Tabulation, State machine |
| Phase 5 — Advanced & Interview Prep | 76–90 | Advanced DP, Advanced Graphs, Mock Interviews | Bitmask DP, Dijkstra, Topological sort |
Time complexity cheat sheet
| Operation | Array | Linked List | Hash Map | BST | Heap |
|---|---|---|---|---|---|
| Access | O(1) | O(n) | O(1) avg | O(log n) | O(1) top |
| Search | O(n) | O(n) | O(1) avg | O(log n) | O(n) |
| Insert | O(n) | O(1) head | O(1) avg | O(log n) | O(log n) |
| Delete | O(n) | O(1) known | O(1) avg | O(log n) | O(log n) |
My progress
- Current phase: Phase 1
- Current day: Day 1 of 90
- Problems solved: 0
- LeetCode streak: 0 days
- Target companies: ___
Quick links
- Phase 1 — Foundations (Days 1–15)
- Phase 2 — Core Data Structures (Days 16–35)
- Phase 3 — Advanced Data Structures (Days 36–55)
- Phase 4 — Core Algorithms (Days 56–75)
- Phase 5 — Advanced & Interview Prep (Days 76–90)
- All 90 Days Reference
Problem sources
| Platform | Use for |
|---|---|
| LeetCode | Primary practice (NeetCode 150 / Blind 75) |
| NeetCode.io | Pattern-based video explanations |
| AlgoExpert | Clean explanations for fundamentals |
| Codeforces | Competitive programming for advanced topics |
| HackerRank | Language-specific practice |
📅 DSA Daily Tracker