PostHere’s a DSA problem-solving cheat sheet that will help you solve 90–95% of questions that come your way.

Here’s a DSA problem-solving cheat sheet that will help you solve 90–95% of questions that come your way. ♦ If the input is an array or string: • Is the array sorted? – Yes: Use Binary Search or Two Pointers. – No: Move to the next checks. • What is the question asking? – Number of ways to do something / Max-Min of something: ▪ If decisions are dependent on each other, use Dynamic Programming. ▪ If decisions are independent, use Greedy. – Is something possible? ▪ Try Backtracking. • Does it involve string manipulation? – Prefix matching: Use Trie. – Building strings or finding distances: Use Stack or Monotonic Stack. • Is it about finding a specific element? – Use a Hash Map or Set. • Does it involve elements being added/removed in a sliding window fashion? – Use a Sliding Window or Counting Hash Map. • Is the problem about continuously finding the max/min element or removing them? – Use a Heap or Monotonic Queue. ♦ If the input is a graph: • Does the question involve finding the shortest path or the fewest steps? – Yes: Use Breadth-First Search (BFS). – No: Use Depth-First Search (DFS). ♦ If the input is a tree (probably binary): • Does the question involve specific depths/levels? – Yes: Use Breadth-First Search (BFS). – No: Use Depth-First Search (DFS). ♦ If the input is a linked list: • Does it involve detecting cycles? – Use Fast and Slow Pointers. • Does it involve reversing or modifications? – Use a prev pointer for reversing. – Use a dummy pointer for maintaining the original head. This flow will help you quickly identify the optimal approach for most DSA problems. React ❤️ for more