Linked Questions

168
votes
3answers
19k 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 ...
3
votes
2answers
231 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 ...
-1
votes
1answer
122 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 ...
2
votes
1answer
108 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 ...
1
vote
1answer
122 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 ...
0
votes
0answers
81 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 ...
94
votes
3answers
26k 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 ...
2
votes
2answers
13k 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 ...
4
votes
2answers
18k 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, ...
11
votes
2answers
502 views

How to prove that $n(\log_3(n))^5 = O(n^{1.2})$?

This a homework question from Udi Manber's book. Any hint would be nice :) I must show that: $n(\log_3(n))^5 = O(n^{1.2})$ I tried using Theorem 3.1 of book: $f(n)^c = O(a^{f(n)})$ (for $c >...
0
votes
4answers
4k views

Proving Quicksort has a worst case of O(n²)

I am sorting the following list of numbers which is in descending order. I am using QuickSort to sort and it is known that the worst case running time of QuickSort is $O(n^2)$ ...
0
votes
2answers
1k views

how to calculate time complexity of non terminating loops

I'm studying about data structures and algorithms in that Time complexity and calculating time complexity of the programs. I just wondered that how to calculate time complexity of non terminating ...
3
votes
2answers
4k views

Using software to calculate the complexity of an algorithm

I am somewhat a beginner, and I have often seen complexity being calculated for various algorithms but they never actually gave me a very clear idea about how it is done. Can someone please point some ...
3
votes
2answers
3k views

What is running time of an algorithm?

What do we mean by running time of algorithms? when we say running time of bubble sort is O($n^2$), what are we implying? Is it possible to find the approximate time in minutes/seconds from the ...
5
votes
2answers
556 views

BigO, Running Time, Invariants - Learning Resources

What are some good online resources that will help me better understand BigO notation, running time & invariants? I'm looking for lectures, interactive examples if possible.

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