Questions tagged [algorithm]
An algorithm is a sequence of well-defined steps that defines an abstract solution to a problem. Use this tag when your issue is related to algorithm design.
algorithm
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What is a plain English explanation of "Big O" notation?
I'd prefer as little formal definition as possible and simple mathematics.
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How do I check if an array includes a value in JavaScript?
What is the most concise and efficient way to find out if a JavaScript array contains a value?
This is the only way I know to do it:
function contains(a, obj) {
for (var i = 0; i < a.length; i++...
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How can I pair socks from a pile efficiently?
Yesterday I was pairing the socks from the clean laundry and figured out the way I was doing it is not very efficient. I was doing a naive search — picking one sock and "iterating" the pile in ...
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What does O(log n) mean exactly?
I am learning about Big O Notation running times and amortized times. I understand the notion of O(n) linear time, meaning that the size of the input affects the growth of the algorithm ...
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What is the optimal algorithm for the game 2048?
I have recently stumbled upon the game 2048. You merge similar tiles by moving them in any of the four directions to make "bigger" tiles. After each move, a new tile appears at random empty position ...
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What is tail recursion?
Whilst starting to learn lisp, I've come across the term tail-recursive. What does it mean exactly?
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Image Processing: Algorithm Improvement for 'Coca-Cola Can' Recognition
One of the most interesting projects I've worked on in the past couple of years was a project about image processing. The goal was to develop a system to be able to recognize Coca-Cola 'cans' (note ...
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What is the best algorithm for overriding GetHashCode?
In .NET, the GetHashCode method is used in a lot of places throughout the .NET base class libraries. Implementing it properly is especially important to find items quickly in a collection or when ...
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Removing duplicates in lists
How can I check if a list has any duplicates and return a new list without duplicates?
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Easy interview question got harder: given numbers 1..100, find the missing number(s) given exactly k are missing
I had an interesting job interview experience a while back. The question started really easy:
Q1: We have a bag containing numbers 1, 2, 3, …, 100. Each number appears exactly once, so there are 100 ...
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Ukkonen's suffix tree algorithm in plain English
I feel a bit thick at this point. I've spent days trying to fully wrap my head around suffix tree construction, but because I don't have a mathematical background, many of the explanations elude me as ...
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Calculate distance between two latitude-longitude points? (Haversine formula)
How do I calculate the distance between two points specified by latitude and longitude?
For clarification, I'd like the distance in kilometers; the points use the WGS84 system and I'd like to ...
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What is tail call optimization?
Very simply, what is tail-call optimization?
More specifically, what are some small code snippets where it could be applied, and where not, with an explanation of why?
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How can I find the time complexity of an algorithm?
I have gone through Google and Stack Overflow search, but nowhere I was able to find a clear and straightforward explanation for how to calculate time complexity.
What do I know already?
Say for code ...
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Count the number of set bits in a 32-bit integer
8 bits representing the number 7 look like this:
00000111
Three bits are set.
What are the algorithms to determine the number of set bits in a 32-bit integer?