Questions tagged [recursion]
For questions about recursion, the practice of calling a method or function from within itself.
167 questions
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can every program still be written without recursion or cyclic calls?
I'm wondering if it was theoretically possible for a compiler to determine maximum stack depth at compile time if a limitation was placed on the program. The limitation being that you can't use ...
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How do compilers work in a language that doesn't allow recursion?
I'm recently learning the programming language, and I wonder how compilers work when the language itself does not allow recursion, like how the compiler or the runtime checkers makes sure that there ...
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How do I create a new class or struct with property of its own type?
I have been trying to figure out if I can create a class or struct with a property that is of the same class or struct. An example would be
struct Number {
var Value: Int = 0
var Rate: Number(...
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Calling recursive method in a loop - Backtracking
I'm confused about a matter that I've been unable to figure out. I'm doing some leetcode problems. In backtracking problems, sometimes we use loop within our recursive method to call the recursion but ...
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Can I use additional parameters in recursion problems?
Okay, I was being interviewed at a company and the interviewer asked me a recursion problem. It was an online interview, so, he had set up the problem statement and a function signature on CodeSandbox ...
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Recursion + Stack/Queue usage in practical life implementation [closed]
I am very new to Data Structures and Algorithms. I want to use recursion + stack/queue in a grocery store inventory program that I am making. However, I can't come up with any good ways of using ...
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Iterative Sorts vs. Recursive Sorts
Naive sorts like Bubble Sort and Insertion Sort are inefficient and hence we use more efficient algorithms such as Quicksort and Merge Sort. But then, these two sorts are recursive in nature, and ...
user351663
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Representing a recursive Structure in OOP
I want to represent an Edifact message in an OOP Language. An Edifact message has the following structure:
message := [ ( segment | segmentgroup ) ]
segmentgroup : = [ ( segment | segmentgroup ) ...
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If the whole point of recursion is to break the problem into multiple smaller problems, what if those problems were solved in parallel?
So I was studying here and I was thinking if the whole point of recursion is to break the problem into multiple smaller problems, what if those problems were solved in parallel? A quick search lead me ...
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How to optimize reusing a large std::unordered_map as a temporary in a frequently called function?
Simplified question with a working example: I want to reuse a std::unordered_map (let's call it umap) multiple times, similar to the following dummy code (which does not do anything meaningful). How ...
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True or false about recursion
I am working on a quiz for a computer science course. I would like to check that the following statement is false:
A recursive call may never generate more than one recursive call for
the ...
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Patterns for tracking state in recursive Haskell code
A frequent pattern in my Haskell code is element-wise recursion for transformation of a list with some carried state generated using the data in the list. Usually, this looks something like this:
...
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Why does GHC represent recursion in Haskell with recursive binders instead of a fixpoint operator?
GHC's Core data type represents recursion with recursive binders in the Let constructor; as I understand it, all let expressions in Haskell are effectively let rec expressions. Why does GHC use this ...
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Question about memory handling of trees and certain sorts on large data sets.
If data structures such as trees and certain sorts(quick sort, merge sort) work using recursive algorithms and recursive algorithms take up a lot of memory space in the stack and can only work on a ...
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An elegant way to detect the end of an asynchronous recursive file search?
Given a recursive subroutine in single threaded environment which starts numerous asynchronous I/O operations and registers callback functions for each of them. This callbacks will be called on the ...
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Memoization in case of recursive interdefined functions in Haskell/Functional Programming?
I was reading Memoization with recursion which tells how for a recursively defined function fun we can do memoization by:
-- Memoization
memoize f = (map f [0 ..] !!)
-- Base cases
g f 0 = 0
g f 1 = ...
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Eliminating recursion
It is easy to eliminate tail recursion.
There are few curious cases where the not-tail recursion can also be eliminated.
Exhibit 1: Fibonacci numbers.
A naive recursive solution
fib(n)
if (n &...
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Efficiency considerations: nested loop vs recursion
I would consider myself an intermediate Python programmer. One of my recent challenges was creating a list of all possible solutions to a given
Countdown problem.
Without getting into too much detail,...
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Why isn't this combinatorial solution equivalent to the recursive solution for finding the number of "paths"?
Here's the problem:
Given an m x n array, get the number of different paths from the top left corner to the bottom right corner, if you can only move down, right, and diagonally down & right.
...
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How does K&R's qsort work?
In the recursion section of K&R's ANSI C book, they demonstrate a
version of quicksort [that] is not the fastest possible, but it's one of the simplest.
--The C Programming Language (ANSI C)...
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Designing the recursive solution
I understand the recursion and find it useful and intuitive while solving problems on trees but for many other problems recursion never fails me to leave puzzled. Recently I was solving the following ...
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how is stack and heap are assigned to each processes?
How multiples processes are stored in the main memory , i understand every process will be divided into the equal size pages and will be stored in the frames of main memory. if whole main memory is ...
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How to mentally keep track of recursion
I have great trouble doing recursion, especially trying to visualize it. A great example is the aging wine problem described in the top answer of this link: https://www.quora.com/Are-there-any-good-...
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Reflexive calls of objects in the same hierarchy
I am not sure how to phrase this. I believe this should have been asked somewhere, but I am unable to find it because I don't know the keywords.
Basically, I have some types like this:
interface Foo
...
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Implementing map with tail recursion
I am trying to solve this exercise. It is about reimplementing the map function in haskell for learning purpose. I found a solution which doesn't browse all the elements of the list (simple linked ...
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