Stick to Basics. I would classify the following data structures as **must know**
Linked List - Single and Doubly
Stack
Queues
Binary Search Trees or general Binary Tree
Heaps
Basic Graph Traversal and Shortest Path
Hashing
Following data structures may be asked. I would say that their probability of being asked is between 50 to 75% -
Tries
Advance Graphs like flow and min-cut etc.
Bit Manipulation
You will probably crack interviews with sufficient knowledge of above.
Following have very low probability of being asked ( < 25%) :
Segment Trees / Binary Indexed Trees
AVL Trees
B+ Trees
Other hard data structures are absolutely unnecessary.
Following Algorithms / Tricks / Topics may also be important :
Memory Management
Basic Co-ordinate geometry - Manhattan Distance, Closest Point Pair
Divide and Conquer
Greedy
Dynamic Programming - Extremely important
Probability and basic Number Theory
Sorting and Searching
Following topics is important for Knowledge / Experience based questions :
OS - Threads, Processes and Locks using Mutex, Semaphores (Operating systems Archives - GeeksforGeeks)
Scalability Issues, RPCs, Rate limiter, etc.
OOP Concepts
Databases - SQL, NoSQL, Writing simple Queries, Transactions, ACID
Linux Commands - sed, grep, ps, etc.
