DSA in 30 Days for Placement Coding Rounds — A Free Roadmap

Most placement coding rounds — service companies (TCS / Infosys / Wipro / Cognizant), product startups, and even mid-size ITs — test the same data-structures-and-algorithms (DSA) toolkit. This is a 30-day roadmap using only free Siksha Sarovar resources.

Week 1 — Foundations & arrays

• Day 1–2: pick a language. C, C++ or Java — use what your campus drives prefer. Python is fine for product startups but slower in some test setups.
• Day 3–4: Data Structures intro — complexity (Big-O), arrays, strings, two-pointer technique.
• Day 5–7: prefix-sum, sliding window, common array problems (Kadane's, max subarray, rotation). Practise in the online compiler with custom stdin.

Week 2 — Linked lists, stacks, queues

• Day 8–10: singly & doubly linked list operations, reversal, cycle detection (Floyd's).
• Day 11–12: stack patterns — balanced parentheses, next greater element, monotonic stack.
• Day 13–14: queues, deques, sliding-window maximum.

Week 3 — Trees, graphs, recursion

• Day 15–17: binary trees, traversals (inorder / preorder / postorder / level-order), height, diameter.
• Day 18–19: BST operations, validate-BST, lowest common ancestor.
• Day 20–21: graphs — adjacency list, BFS, DFS, cycle detection, topological sort.

Week 4 — Hashing, DP, system fundamentals

• Day 22–23: hashing — frequency maps, anagrams, two-sum, longest substring without repeating characters.
• Day 24–26: introduction to dynamic programming — Fibonacci memo, 0/1 knapsack, longest common subsequence, coin change.
• Day 27–28: DBMS SQL basics + Computer Networks 5-mark concepts (these are routinely asked alongside DSA).
• Day 29: aptitude practice in Competitive — many service-company rounds gate DSA behind aptitude.
• Day 30: full mock — pick a 90-minute time-boxed problem set, run every solution in the online compiler.

Tools to use throughout

• Online compiler — Python, Java, C, C++, C#, JavaScript, PHP, SQL with stdin support. No installation.
• AI Tutor — explains tricky DSA solutions in plain English / Hindi / Hinglish. Great for "why did this approach work?" follow-ups.
• Live Quiz — group-revise with classmates before campus drives.

Where students from each college apply this

DSA roadmaps work the same regardless of college, but if you want college-specific landing pages with dedicated FAQs and tracks see — DTU, NSUT Dwarka, MAIT Rohini, BPIT Rohini, VIPS-TC Pitampura, Amity Noida, Manav Rachna.

Done with the 30 days? Generate a free verifiable certificate for the courses you finished and put it on LinkedIn alongside your placement profile.