I used to solve DSA problems randomly, without a strategy. After multiple rejections, 7–8 months of trial and error, and 800+ problems solved, I finally found what works → mastering the right patterns.
✅ Sliding Window: For subarray/substring problems
✅ Binary Search: Rotated array, lower/upper bound
✅ DFS & BFS: For both trees and graphs
✅ Shortest Path: Dijkstra’s, Bellman-Ford, 0-1 BFS
✅ Dynamic Programming: All key patterns
✅ Linked List: Especially two-pointer problems
✅ Tries: For prefix-based problems
✅ Recursion & Backtracking: For permutations, combinations, etc.
✅ Sliding Window: For subarray/substring problems
✅ Binary Search: Rotated array, lower/upper bound
✅ DFS & BFS: For both trees and graphs
✅ Shortest Path: Dijkstra’s, Bellman-Ford, 0-1 BFS
✅ Dynamic Programming: All key patterns
✅ Linked List: Especially two-pointer problems
✅ Tries: For prefix-based problems
✅ Recursion & Backtracking: For permutations, combinations, etc.
Your resume opens the door, but your projects seal the deal. No more to-do lists or weather apps – it’s time to build something that screams innovation. 💥
🔥 Real-world project ideas to stand out:
🔹 AI Agentic Assistant – Build a ChatGPT-powered personal finance or coding mentor.
🔹 Advanced Monitoring System – Think Prometheus + Grafana + custom anomaly detection using ML.
🔹 End-to-End DevOps Pipeline – Real-time CI/CD, Docker + K8s with self-healing microservices.
🔹 Open Source Contribution – Get on GitHub and contribute to trending AI or backend frameworks.
🔹 Smart SaaS Dashboard – Role-based access, audit logs, webhooks, billing – the whole deal.
🥂Stop listing skills, start showing impact. Show them what you can build.
🔥 Real-world project ideas to stand out:
🔹 AI Agentic Assistant – Build a ChatGPT-powered personal finance or coding mentor.
🔹 Advanced Monitoring System – Think Prometheus + Grafana + custom anomaly detection using ML.
🔹 End-to-End DevOps Pipeline – Real-time CI/CD, Docker + K8s with self-healing microservices.
🔹 Open Source Contribution – Get on GitHub and contribute to trending AI or backend frameworks.
🔹 Smart SaaS Dashboard – Role-based access, audit logs, webhooks, billing – the whole deal.
🥂Stop listing skills, start showing impact. Show them what you can build.
This will help you solve 90% of all DSA problems in interviews (based on my experience over the last 5+ years)
◄ Array / String Inputs
1. Is the array sorted?
→ Use Binary Search, Two Pointers, or Prefix Sums
2. Optimization problems (Max/Min/Subarray)?
→ Think Sliding Window, Dynamic Programming, or Greedy
3. Looking for duplicates / counts / frequencies?
→ Use HashMap, HashSet, or Counting Array
4. Need substrings or fixed-size subarrays?
→ Apply Sliding Window with Two Pointers
5. Frequent min/max in window?
→ Use Monotonic Queue, Deque, or Heap
6. Generating subsets, permutations, combinations?
→ Use Backtracking
7. Matching / parsing characters?
→ Use Stack, especially for Balanced Parentheses, Infix/Postfix
If you want to solve problems fast and with solid accuracy, you need to think in patterns.
Without patterns, you can solve every problem in an interview that you’ve seen once, but once you see a new problem, you will get stuck.