DSA & Problem Solving

A structured 500-problem path instead of random grinding, aimed at Indian placement rounds.

1. Step 01

   Complexity

   Time and space analysis, amortised cost and recognising the target complexity from constraints.

   Big-O

2. Step 02

   Arrays & strings

   Two pointers, sliding window, prefix sums and in-place tricks.

   ArraysTwo Pointers

3. Step 03

   Hashing & sorting

   Frequency maps, custom comparators, binary search on answer.

   HashingBinary Search

4. Step 04

   Linked lists, stacks, queues

   Pointer manipulation, monotonic stacks and deque patterns.

   StacksQueues

5. Step 05

   Trees & graphs

   Traversals, BST properties, BFS/DFS, topological sort, shortest paths, union-find.

   TreesGraphs

6. Step 06

   Dynamic programming

   Recursion to memoisation to tabulation across knapsack, LIS, grids and strings.

   DPRecursion

7. Step 07

   Contest & mock rounds

   Timed sets, dry-running on paper and explaining approach before coding.

   Mocks