Here’s a priority order based on difficulty and frequency in FAANG interviews, categorized into High, Medium, and Low priority.

Resources

🔴 High Priority (Most Frequent & Essential for FAANG)

1. Arrays
   • Kadane’s Algorithm (Max Subarray Sum)
   • Prefix Sum & Difference Array
   • Two Pointer Technique
   • Sliding Window (Fixed & Variable)
   • Dutch National Flag Problem
   • Next Permutation
   • Merge Intervals
2. Linked List
   • Reverse a Linked List (Iterative & Recursive)
   • Cycle Detection (Floyd’s Cycle)
   • Merge Two Sorted Linked Lists
   • Intersection of Two Linked Lists
   • LRU Cache (Using HashMap + DLL)
3. Stack & Monotonic Stack
   • Next Greater Element
   • Largest Rectangle in Histogram
   • Trapping Rain Water
   • Asteroid Collision
   • Min Stack
4. Queue & Deque
   • Implement Queue using Stack
   • Sliding Window Maximum (Using Deque)
5. Sorting
   • Bubble, Selection, Insertion, Merge & Quick Sort
   • Bucket Sort & Counting Sort
6. Binary Search
   • Binary Search on Answer (Aggressive Cows, Split Array, Median of Two Sorted Arrays)
   • Lower & Upper Bound
   • Peak Element
   • Search in Rotated Sorted Array
7. Tree & BST
   • Inorder, Preorder, Postorder Traversal
   • Lowest Common Ancestor
   • Diameter of a Binary Tree
   • Validate BST
   • Binary Tree to DLL
   • Morris Traversal
   • Serialize & Deserialize Binary Tree
8. Heap (Priority Queue)
   • Kth Largest/Smallest Element
   • Top K Frequent Elements
   • Merge K Sorted Lists
9. Graph (Very Important!)
   • BFS & DFS
   • Cycle Detection (Directed & Undirected)
   • Topological Sort (Kahn’s Algo, DFS)
   • Shortest Path (Dijkstra, Bellman-Ford)
   • MST (Prim’s, Kruskal’s)
   • Strongly Connected Components (Kosaraju, Tarjan’s Algo)
   • Union-Find (DSU) & it’s optimization
   • 0-1 BFS / Multi-Source BFS
   • Bipartite Graph Checking
10. Dynamic Programming
    • 1D DP
    • 2D DP
      • String DP
      • Knapsack (0/1 Knapsack, Unbounded)
      • Matrix Chain Multiplication
    • Subset DP
      • Partition Equal Subset Sum
      • Count of Subsets with Given Sum
    • Digit DP
    • Partition Subset
    • Hash + DP
    • DP - Stocks
    • Minimax DP
    • DP on Grid
    • DP + Alpha (Tricks/DS) (optional)
    • DP on Trees (optional)
    • DP on Graphs (optional)

🟠 Medium Priority (Important but Not Always Asked)

1. Greedy Algorithms
   • Interval Scheduling (Non-overlapping Intervals)
   • Gas Station Problem
   • Jump Game
   • Job Sequencing
   • Job Scheduling with Deadlines
   • Interval & line sweeping algorithm
2. Trie
   • Implement Trie (Insert, Search, Delete)
   • Word Break Problem
   • AutoComplete System
3. Modular Arithmetic
   • Fast Exponentiation (Binary Exponentiation)
   • Modular Inverse (Fermat’s Theorem)
   • GCD & LCM
4. Bit Manipulation