maximaxi's blog

How are Segment Trees used in Competitions?
By maximaxi, history, 9 years ago, In English

Hello, I'm just getting started with Segment Trees and I'm curious as to what they can be used for in terms of programming competitions. I know the basic RMQ, GCD, and cumulative sum concepts but I'm not sure what else they can be used for, and what types of problems I should look out for to apply segment trees with.

Any applications and/or problem links would be appreciated.

Thanks for this amazing community,

Max

Edit: Thanks for your responses.

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9 years ago, # |
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Did you see this?

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    9 years ago, # ^ |
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    Not yet; you (and the author) have been very helpful, thanks!

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9 years ago, # |
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I'm also a beginner but i can just share what i have learnt till now.

RMQ,BIT,Cumulative Sum Concept and Sqrt Decomposition data structures are used when there aren't much complex operations.For example find the sum of given range in a array or find the maximum value in a range.Defintely you can also solve them using segment tree as well.

But when you need to apply too many complex operations(like range update) and also need extra variables(or even a built in ds like array/map/vector) to solve the problem then you must use segment tree.For example when you need to find number of distinct elements in a range,find the GCD of all elements in a range or sum/multiplication of elements in a range.And all of them includes range update like(changing value/adding new value/multiplying with new value).

You can check this site for more variations of data structure problems :)

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9 years ago, # |
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Auto comment: topic has been updated by maximaxi (previous revision, new revision, compare).

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9 years ago, # |
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This post has a good implementation of segment trees.

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9 years ago, # |
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http://a2oj.com/Category.jsp?ID=25

Lots of problems related to segtrees.

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    9 years ago, # ^ |
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    Awesome, time to get to practice. :) You rock

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9 years ago, # |
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Just in time, I would say. http://codeforces.net/blog/entry/20592 :)

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