So most people say that the most important things for INOI and dp and graphs but what are the most import data structures?

Stacks, Queues, Priority Queue, Heaps.

I think knowing about Disjoint Set datastructure (UFDS) may also be helpful.

The most you may require is sets and maps according to me

Stacks, Queued, Heaps, Hashing and graph is also important in my opinion.

Arrays and strings are by far the most important data structures in INOI Boring? Maybe. Important? Yes.

The most important non-trivial data structure in INOI is the hash map because of its versatility and constant-time operations. If you don’t know how to use a hash map, learn now.

Next in line are linked lists, stacks, queues, and trees. You need to know these inside and out.

In the next tier are graphs, priority queues, and heaps. You should still know these, but they appear more rarely.

In the bottom tier are lesser known data structures like bit sets, tries, disjoint sets, specific cache implementations, etc. It doesn’t hurt to prepare for some of these, although they appear most rarely.

And yes map, unordered map.

As you have correctly stated dp and graphs are most popular type of problems so data structures related to these also become important i.e Arrays (for dp) and stacks,queues,trees,adjacency list/matrix, priority queues etc. (for graphs) . Knowing about these inside out is critical and first thing to learn but equally important is the fact that how you use Data Stuctures in libraries built in for your language (eg using Sets maps etc. Built in STL). Apart from this you may check out bitset in STL it is sometimes quite useful.

Do you know of some tutorials

Yeah dear for Stacks & Queues i would suggest https://www.youtube.com/watch?v=92S4zgXN17o&list=PL2_aWCzGMAwI3W_JlcBbtYTwiQSsOTa6P also you can look at www.geeksforgeeks.org tutorials for Heaps https://youtu.be/t0Cq6tVNRBA?t=23 there is also www.xoax.net tutorials.

Seeing you active after long time at the Forum.Can you give more idea on how should i prepare for this 20 days for INOI.

I don’t that there is enough time to understand how they work and also how they are implemented so can you give me some tutorials on using inbuilt data structures.

Didn’t get you, Can you be more clearer?

Yes, but remember the priority_queue is somewhat different than what you’d expect

Just chill… don’t panic, and don’t ignore any subtask in INOI (I didnt get to IOITC last yr bcoz of this )