This repo contains journey of my DSA learnings.
I will be providing codes of some standard algorithms and frequently used concepts here (in C++) in this repo, you can refer to the code and the concepts for your needs and understanding.
There are many patterns that can be recognized when solving data structures and algorithms (DSA) questions. Identifying these patterns by reading can help you solve problems more efficiently within your limited time. Over time and with practice, people start recognizing these patterns.
Let’s understand a few general patterns that you can use in your future journey:
Sorted Input:
- Apply binary search for efficient element lookup.
- Use the two-pointer technique for problems involving pairs or segments.
Unsorted Input:
- Apply dynamic programming for questions related to counting ways or optimizing values.
- Use backtracking for problems that ask for all possibilities or combinations (this is also a suitable fallback if dynamic programming isn’t going to work).
- Use a Trie for prefix matching and string-building scenarios.
- Use a hash map or set to find specific elements quickly.
- Implement a monotonic stack or sliding window technique for managing elements while continuously finding maximum or minimum values.
Input is a Graph or Tree:
- Use DFS to explore all paths or when the question does not require finding the shortest path.
- Use BFS when the question asks for the shortest path or fewest steps.
- For binary trees, use DFS if the problem involves exploring specific depths or levels.
Linked List Input:
- Use techniques involving slow and fast pointers or "prev" and "dummy" pointers to facilitate certain operations if you are unsure how to achieve a specific outcome.
Note: There's so much more to this pattern! We just wanted to give you a glimpse of what pattern recognition boils down to in its simplest form. Feel free to add your own flair and create a detailed chart!
