26k views

Is there a system behind the magic of algorithm analysis?

There are lots of questions about how to analyze the running time of algorithms (see, e.g., runtime-analysis and algorithm-analysis). Many are similar, for instance those asking for a cost analysis ...
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254 views

Determining Big O [duplicate]

i<--2 while (i<n) someWork (...) i <-- power (i,2) done Given that someWork(...) is an O(n) algorithm, what is the worst case ...
176 views

How to get an O(n) for a search algorithm [duplicate]

Given an two sorted arrays X and Y, both of size n. Determine if there is an element x of X and an element y of Y such that x = 3y. The algorithm needs to run in linear time in the worst case. At the ...
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115 views

Analysis of Algorithms: Applying Concepts [duplicate]

I believe I understand the concepts of algorithm analysis. However, I'm not fully confident in applying those concepts. I'd appreciate help in bridging the gap between concept and application. I ...
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1 vote
144 views

What exactly is bigO notation? [duplicate]

I've heard of bigO notation but I don't really understand how do I determine it for my code and what exactly does it represent? I heard that there are two: RunTime Memory Complexity How can I learn ...
82 views

How to calculate Complexity Time O()? [duplicate]

Can anybody give me a way that i can use to calculate Complexity Time problems, i mean a way that will work on any complex code whatever it was. I can solve basic problems, but whenever the problem ...
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35k views

How does one know which notation of time complexity analysis to use?

In most introductory algorithm classes, notations like $O$ (Big O) and $\Theta$ are introduced, and a student would typically learn to use one of these to find the time complexity. However, there are ...
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35k views

Time complexity of a backtrack algorithm

I've developed the following backtrack algorithm, and I'm trying to find out it time complexity. A set of $K$ integers defines a set of modular distances between all pairs of them. In this algorithm, ...
15k views

How is the complexity of recursive algorithms calculated and do they admit better complexity than non-recursive algorithms?

How are asymptotical time complexities calculated for recursive algorithms? Recursive algorithms call themselves and therefore take up more space compared to non-recursive algorithms. But are they ...
• 129
705 views

1 vote
3k views

Worst case time complexity of heap sort

I was learning about heaps, and came to know that the worst case time complexity of heap sort is Ω(n lg n). I am having a hard time grasping this. My reasoning is as follows: ...
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