A six-week DSA plan for placement season

Pick one language (Java, C++ or Python) and stay with it for the whole plan. Aim for about two hours a day: one hour of new problems and one hour of revision.

Week 1: arrays, strings and hashing

• Prefix sums, frequency counting with a hash map, two-sum style lookups.
• Two pointers and sliding window.
• Target: 20 easy and 5 medium problems.

Week 2: sorting, searching and recursion

• How merge sort and quick sort work, and their complexity.
• Binary search, including searching on the answer.
• Recursion and backtracking: subsets, permutations, N-Queens.
• Target: 15 problems, including 5 binary search variants.

Week 3: linked lists, stacks and queues

• Reversing a list, detecting a cycle (fast and slow pointers), merging sorted lists.
• Stack problems: balanced brackets, next greater element, monotonic stack.
• Queue and deque: sliding window maximum.
• Target: 15 problems.

Week 4: trees

• Traversals (inorder, preorder, postorder, level order), height, diameter.
• Binary search trees: insert, search, validate, lowest common ancestor.
• Heaps and priority queues: top k elements, merging k sorted lists.
• Target: 15 problems.

Week 5: graphs

• Adjacency lists, BFS, DFS, counting connected components.
• Cycle detection, topological sort, shortest paths with BFS and Dijkstra.
• Target: 12 problems.

Week 6: dynamic programming and mock tests

• 1D DP: climbing stairs, house robber. 2D DP: grid paths, longest common subsequence, 0/1 knapsack.
• Two timed mock tests of 90 minutes each, then review every problem you missed.
• Target: 12 DP problems.

Every week

• Keep a notebook or sheet of mistakes: the problem, the idea you missed, and the complexity.
• On Sunday, solve three problems from earlier weeks again without looking at your old code.
• Say your approach aloud before coding; interviews test explanation as much as code.
• Track your progress with UniCircle interview prep: data structures and algorithms.