Questions tagged [set]
A set is a collection in which no element is repeated, which may be able to enumerate its elements according to an ordering criterion (an "ordered set") or retain no order (an "unordered set").
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Rewriting the java.util.concurrent.ConcurrentSkipListMap to a version without concurrency constructs
I have essentially rewrote the java.util.concurrent.ConcurrentSkipListMap into a version without concurrency constructs (...
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Compare and merge sets from unstructured variables for automatic differentiation
I have developed an automatic differentiation module for my software. Usually AD comes in two forms; forward mode or reverse mode and very clever approaches, beyond me, might mix both. Typically the ...
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Set-like Operation in C - Advent of Code 2021 Day 3
I am relatively new to C programming and am currently completeing challenges of Advent of Code 2021 to elevate my skills. I am excited to share my solution for the puzzle on Day 3 and am eager to ...
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Collection that uses a bitset to store a huge set of unique integers from a given range (rev. 1)
Some (skippable) context:
I'm writing program that minimizes an arbitrary logical function. Such function takes an unsigned integer as an argument and returns either ...
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Comparison of two excel files ignoring line order
Below is a simple method which compares contents of two excel files ignoring the line order.
This method is working as expected.
But, one of my peers in their code review mentioned that initializing ...
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IPv4 filter in Java
I have a simple class for representing IPv4-addresses via int values, and a simple IP-address filter that works like a set of IPv4-addresses.
...
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Compressed output of set in Python
In order to provide a better output of sets with many consecutive elements (a similar class could be written for a list or tuple,...
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Yet another Wordle Game
This Jupyter Notebook code for the Wordle game works. After a lot of fixes, I have it working as it should. The code is a jumbled mess. I am open to any suggestions and/or criticism of my code. I am ...
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SortedIntSet: a set of integers that can be iterated in ascending order in O(N) time
I needed a set with the following properties:
can be iterated in ascending or descending order in \$O(N)\$ time
the usual set operations (contains, add, remove, discard) can still be done in \$O(1)\$
...
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Vectorset, a faster std::set
I decided to implement a vectorset, which is intended to be faster than std::set for the 3 fundamental operations, namely insert,...
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How many times element of one array occurs in another array?( HackerRank sparse arrays problem)
with basic knowledge of multiset and vectors in c++ I solved the following problem.
How can I improve my code and also handle any input errors?
Problem statement:
There is a collection of input ...
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Radio with channels
Realize the Radio and Channel classes that represent radio and a radio station. The radio class offers an argumentless constructor and the following methods:
addChannel: stores and returns a new ...
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A simple Java integer integer hash set - follow-up 2
(See the previous version.)
Now I have this:
com.github.coderodde.util.IntHashSet:
...
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A simple Java integer hash set - follow-up
(See the previous version.)
(See the next version.)
After incorporating changes in the previous post, I came up with this implementation. However, I left hashing as it is.
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A simple Java integer hash set
(See the next version.)
The following data structure implements a hash table based set for int values:
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278
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Managing duplicate class instances in a javascript Set
I have a class called Thing. For simplicity, let's say it initializes with a unique id, and that's all that's unique about it:
...
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Take element of a Set collection depending on the value of another element
I had to populate the fields of a Service object using a Set (HashSet) with any configuration parameters -> ...
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Sort an array of integers with a hashset
I was trying to make a sorting algorithm for an array of integers. Here's are the steps/theory:
It turns an array into a HashSet, iterates over every integer value ...
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Filtering a List based on a Suffix and avoid duplicates
I was wondering if there is a better way to solve this issue.
I have a list like this:
...
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Find a powerset of a set in C
The code below is an implementation of purely recursive solution to find a powerset of any given set. The input set is a string, and the output - array of strings. Both of them are wrapped into a ...
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Set operations on a tree / Hierarchical set class
Initially, I posted this question on StackOverflow. I wanted to know if there's an existing library that implements the concept I have in mind, which is the following.
I want to define a hierarchy/...
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Set<T> data structure in C#
The following data structure is meant for manipulating algebraic/mathematical sets.
I want Set<T> to be compatible and interchangeable with any similar data ...
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Solving Exact Cover by Three Products in Python
I'm a computer-science hobbyist and found an NP-complete problem that is similar to both subset-product and Exact Cover by 3-sets.
Here is a Reduction of Exact-Cover into my problem. I am multiplying ...
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Finding data relations of json paths in python
I am kind of new to python, so I am pretty sure there are way better elegant ways to do this.
I have made a function that is able to compare two list of possible json object paths, and detect what ...
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Bloom Filter in Haskell
I recently implemented a Bloom Filter in Haskell and, although I am not new to functional programming, I am a beginner when it comes to Haskell itself.
I'll gladly take any feedback regarding the ...
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Remove elements compared with other elements in a Set based on a condition
Simplified the actual problem to focus on comparing/removing performance.
Given a set S with n elements , find the most optimal way to compare each element to all others until a condition is met that ...
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Finding which items have at least one common value with other items
I have the following collection :
...
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Immutable Keyed Set
Description
An immutable keyed set is a readonly collection of elements without
duplicates or null values having each of the elements linked to
exactly one key.
Example
This simple example ...
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4
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2
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115
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Ensure difference between sets
An endpoint that my application interacts with allows you to specify which fields are returned in the JSON result. My application will then map the JSON to a POJO using Jackson. Quite often I add more ...
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Python set based solution to Subset Sum
Working on the 2 element subset sum problem (finding two numbers in a list that sum to a given value), I came up with a relatively short solution code-wise.
The code could fit on a single line but I'...
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Generic Macro Generated Hashset in C
The Hashset uses open addressing, linear probing and Robin Hood hashing for handling collisions. It comes with insert and remove ...
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Custom Hashset in Java
I have written this custom hashset and though it isn't completed yet, I would like to know if there is anything I am overlooking in terms of clean code conventions. My aim was also to apply generics ...
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unordered_set: a hash table -based set data structure in C89
In this post, I present a hash table -based set data structure written in C89:
unordered_set.h
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107
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java.util.Set extension/implementation
Lately, I was working on some experimental java.util.Set extension, IdSet:
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Powerset of collection in Clojure
Similar to this question, here's another implementation. Assume the input is already a set.
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Sort int array by frequency then value
Problem
Take an array of ints as input and run a special sorting algorithm on it. This algorithm must first sort by int frequency, less frequent first, then sort by value.
For example ...
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Data Structures for Counting Duplicates and using std::vector::erase
Problem
Dupe detection for a vector of ints. I simply want a count of the unique input characters that occurred at least twice. The goal is to count a dupe only once and ignore that input character if ...
- 1,017
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Test for an array being subset of another master array
I was trying to build a small utility function to check if an array is part of other array. It's testing if an array is a subset of another master array.
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Possible letter combinations of a dial pad in linear time using a recursive approach
Time complexity: I walk the initial unzipped array of keys representing the number O(N) backwards. I then do an inner walk of the proceeding array of letters *O(L^2), mapping it to every value in the ...
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All subsets of a String in java using recursion
I wrote this code for printing all sets of a String. It also prints the empty subset. Is this the right approach
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Finding Repeat and missing numbers in an array
Problem Statement:
You are given a read-only array of n integers from 1 to n. Each
integer appears exactly once except A which appears twice and B which
is missing.
Return A and B.
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Grow-only set (CRDT)
I made up a quick and dirty implementation of the G-Set in C#. I was hoping for some feedback on my approach. I'm not totally happy with having the payload public but I can't see that I'm gaining ...
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From a set of words, output all words that fit a string of random letters (like Scrabble)
I am in my first year of programming with Python 3 and am wondering if anyone had a better way to program this problem. When the user provides up to 7 random letters as a single string, the program ...
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set implementation based on an array
I was supposed to implement set without using any implemented structures. I would love to know what can I correct in my code, because I am not that much satisfied with its quality, so if you have any ...
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Implementation of a shift operation for Set in JavaScript that emulates the one for arrays
I discovered that the JavaScript sets are ordered but don't offer a method to take the first element out of the set. For the arrays this operation exists and it's called shift.
A very basic ...
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Finding the number of ways to partition {1,2, ..., N} into p1 and p2 such that sum(p1) == sum(p2)
I am trying to write a space and time efficient algorithm to calculate the number of ways to partition a set of integers {1, 2, ..., N} into two partitions such that the sums of integers in the two ...
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Ruby Connected Components in a Graph
I've written the following code to find the connected components of a graph in ruby, but it is quite slow since I don't use any sensible data structure for the disjoint sets, and hence find_set is ...
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is_subset Python implementation
I wanted to ask for a code review for my implementation of Set:
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Concurrent HashSet
I've recently been using HashSet and locking on each method, I found this to not only be a lot of work (was using it in a lot of places) but I started to see inconsistency in my code.
I later decided ...
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Finding common Integers between two lists
Write a method numInCommon that takes two Lists of integers as
parameters and returns the number of unique integers that occur in
both lists. Use one or more Sets as storage to help you solve this
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