*You can spot 90% of the DSA patterns in Leetcode questions with this DSA patterns identification cheatsheet. It will help you identify which questions will be solved by which pattern based on keywords.* → Two Pointers ◘ opposite ends ◘ merging intervals ◘ skipping duplicates ◘ partitioning array → Sliding Window ◘ minimum length ◘ longest unique ◘ at most/at least K ◘ replace/transform window → Binary Search ◘ find boundary ◘ peak element ◘ rotated array ◘ kth smallest/largest → Fast & Slow Pointers ◘ cycle start node ◘ repeated number ◘ palindrome check ◘ intersection node → Breadth-First Search (BFS) ◘ minimum steps ◘ multi-source ◘ zigzag/spiral ◘ expand frontier → Depth-First Search (DFS) ◘ enumerate all paths ◘ subtree sum ◘ postorder processing ◘ coloring/marking → Backtracking ◘ valid arrangements ◘ decision tree ◘ partial solution ◘ pruning/boundary check → Dynamic Programming ◘ optimal substructure ◘ table filling ◘ count ways ◘ partitioning problem → Greedy ◘ interval scheduling ◘ earliest/latest deadline ◘ minimum jumps/coins ◘ lexicographical choice → Hashing / Hash Table ◘ group anagrams ◘ detect duplicates ◘ count pairs ◘ custom key mapping → Union Find (Disjoint Set) ◘ number of islands ◘ friend circles ◘ redundant connection ◘ find root → Topological Sort ◘ course ordering ◘ dependency resolution ◘ prerequisites ◘ cycle in directed graph → Trie ◘ word break ◘ longest prefix ◘ search suggestions ◘ word replacement → Heap / Priority Queue ◘ running median ◘ merge k sorted ◘ reorder tasks ◘ smallest/largest in stream *React ❤️ for more*