Questions tagged [sieve-of-eratosthenes]
The Sieve of Eratosthenes is a prime-finding algorithm developed by the ancient Greek mathematician Eratosthenes. It works by writing down as many numbers as needed and then, traversing from lowest to highest, cross out all multiples of a number, beginning with 2. The numbers that remain are considered prime and the lowest of it will be used for the next run.
177
questions
2
votes
1
answer
93
views
Sieve of Eratosthenes in F#
after looking at the pseudocode for the Sieve of Eratosthenes on wikipedia I tried implementing a similar version using F#. The code runs just fine, that is, it returns all prime numbers up until a ...
4
votes
1
answer
102
views
Segmented Sieve of Eratosthenes with wheel factorisation
Problem
I have a project in which I implemented variants of the Sieve of Eratosthenes as well as benchmarking and profiling harnesses for these (which can be ran with ...
- 259
2
votes
2
answers
88
views
5
votes
5
answers
658
views
Implementation of Sieve of Eratosthenes in Java
I have implemented Sieve of Eratosthenes in Java as follows. Is there a way I can modify the below code to make it more efficient?
The current execution time is
0.8481224 seconds
...
5
votes
5
answers
663
views
Comparing 2 distinct sieve of Eratosthenes algorithms in Java
In this post, I will present and compare two distinct algorithms for sieve of Eratosthenes:
com.github.coderodde.math.prime.PrimeFinder
...
- 25.3k
13
votes
1
answer
308
views
Sieve of Eratosthenes in Vyxal
I'm trying to learn the golfing language Vyxal because I occasionally contribute to it, and I'm slightly ashamed I can't even use it. To do this, I started with implementing the Sieve of Eratosthenes ...
- 499
5
votes
3
answers
151
views
Optimize Sieve of Eratosthenes for big numbers in Python
I'm solving Euler exercise number 7 and trying to go a bit further on bigger primes.
It is too slow with big numbers. I've been reading ways to optimize the sieve, but I would like to ask people with ...
- 63
4
votes
2
answers
148
views
Sieve of eratosthenes: My optimized version
I wrote a simple prime number program that checks if a number is prime or not using sieve of eratosthenes, I also wrote an optimized version that only generates the ...
- 1,858
21
votes
4
answers
5k
views
Why is my Sieve of Eratosthenes using generators so slow
This is my prime sieve based on the Sieve of Eratosthenes.
...
- 329
2
votes
1
answer
91
views
A Sieve of Eratosthenes
I have written this Sieve of Eratosthenes. This is a bit of software that will find all of the prime numbers between 2 and n, where n is a user-defined value.
The code does seem quite bloated and any ...
- 249
6
votes
3
answers
923
views
Prime sieve generator
I wrote a simple prime sieve in Python. But it ended up looking... ugly. I included a few of the most basic optimizations. When posting this question SE suggested a bunch of questions on the same ...
- 253
2
votes
2
answers
95
views
Sieve of Eratosthenes optimisation
I'm implementing Sieve of Eratosthenes by working with multiples of 30 and comparing it to multiples of 3 from a previous answer
code for multiples of 30:
...
- 153
1
vote
0
answers
93
views
Zen and the Sieve of Eratosthenes - Part 1: A Basic Windowed Sieve
The Sieve of Eratosthenes is one of the oldest known algorithms and yet it is still the best method for sieving prime numbers in bulk in many situations. It is brutally simple, but to make it brutally ...
- 2,643
2
votes
1
answer
179
views
Further Optimizing a Segmented Sieve of Eratosthenes
I've implemented a Segmented Sieve of Eratosthenes that assumes each segment is about length \$ \sqrt{N}\$ for some upper limit \$N\$.
I further optimized the function by skipping all the evens when ...
- 171
4
votes
4
answers
922
views
Sum of primes under a certain number
I have tried two different methods to find the sum of primes under a certain number. However both of these methods end up taking a very long time for large numbers. How can I optimise either of these ...
- 199
4
votes
1
answer
97
views
Prime Number Table, i.e. List<int>
I have written many variations of the Sieve of Eratosthenses, which is the fastest way to generate a large collection of primes. (@slepic asked for clarification, which I provide in an answer below. ...
- 5,522
7
votes
2
answers
809
views
Project Euler problem 50
I was just trying Project Euler problem 50.
The prime 41, can be written as the sum of six consecutive primes: 41
= 2 + 3 + 5 + 7 + 11 + 13
This is the longest sum of consecutive primes that ...
- 2,710
7
votes
1
answer
195
views
Understanding RSA key generation and implementation in Java
Here is an attempt to leverage Java's BigInteger class to implement the RSA algorithm, as well as md5 and sha512 hashing functions to generate keys for what I hope to be strong cryptography. My prayer ...
- 79
11
votes
2
answers
710
views
Segmented wheel Sieve of Eratosthenes in Python
Here is a new version of a segmented and wheel factorized Sieve of Eratosthenes. It currently uses mod 30 wheel factorization to eliminate multiples of 2, 3, and 5 in the sieve data structure to gain ...
- 185
8
votes
1
answer
334
views
Segmented and wheel factorized prime generator in Python
I recently discovered that it is much faster to generate primes using a Sieve of Eratosthenes (SoE) with a boolean array data structure than with a heap. Since then I have been looking for fast and ...
- 185
1
vote
2
answers
183
views
Optimizing the Sieve of Eratosthenes for prime generation
I've been on a Project Euler spree and I've been solving problems and as you might know, many of them require you to use prime numbers. I've been using the following code to generate and store primes ...
- 335
4
votes
1
answer
373
views
Incremental Sieve of Eratosthenes Generator
So I was fiddling around with the Euler challenges. One of the things they mentioned in their discussions of the solutions is the Sieve of Eratosthenes and that you can only use it when you know an ...
- 2,889
3
votes
2
answers
788
views
Sum of primes up to 2 million using the Sieve of Eratosthenes
I've solved question 10 on Project Euler using the Sieve of Eratosthenes, what can I do to optimize my code?
...
- 45
13
votes
3
answers
2k
views
Prime sieve in Python
I was trying to write Sieve for the first time and I came up with this code:
...
- 509
5
votes
1
answer
74
views
Prime Sieve and brute force #2
Based on my previous attempt.
Prime Sieve and brute force
Trying to make the interface simpler I have moved all the code into a class. This way I can keep track of the ...
- 91.5k
14
votes
3
answers
1k
views
Prime Sieve and brute force
Got caught up with this morning's C++ question.
So I thought I would have a go.
SO here is my attempt at printing the first 1001 primes.
...
- 91.5k
9
votes
3
answers
1k
views
3
votes
1
answer
210
views
Efficiency of a recursive implementation of the Sieve of Erasthotenes in Python
I implemented the Sieve of Erasthotenes recursively using filter and I was wondering how efficient this implementation is and wether a non-recursive implementation ...
- 33
4
votes
2
answers
319
views
Incremental Sieve of Eratosthenes using iterators
I am in the process of learning Rust and am still having some issues with borrowing and ownership. I find myself trying to borrow mutable references that are already borrowed as immutable references ...
- 201
1
vote
0
answers
61
views
Incremental Sieve of Eratosthenes using unstable generators [duplicate]
I am in the process of learning Rust and am still having some issues with borrowing and ownership. I find myself trying to borrow mutable references that are already borrowed as immutable references ...
- 201
2
votes
1
answer
400
views
Simple Sieve of Eratosthenes in Python 3
So yet another Sieve of Eratosthenes in Python 3.
The function returns a list of all primes smaller but not equal max_n.
The motivation is, as a practice, a ...
- 195
2
votes
1
answer
931
views
Fast Prime Sieve (Python Implementation)
A modified version of the prime sieve. I actually doubt it could be implemented any faster, but I might be wrong:
...
- 1,796
0
votes
1
answer
75
views
Computing a prime table in Rust
My objective is computing a table of primes up to n, where n is a natural number passed as an argument to the prime_table function.
Here is src/lib.rs:
...
2
votes
1
answer
294
views
Faster Sieve of Eratosthenes
This is an implementation of the Sieve of Eratosthenes :
It takes advantages of the fact that all primes from 5 and above can be written as 6X-1 or ...
- 857
2
votes
2
answers
132
views
Project Euler #10 (sum of primes less than two million) in Clojure
I'm new to Clojure and using some Project Euler problems to familiarize myself with the language's capabilities. Problem #10 asks to find the sum of all primes less than two million.
I wanted to ...
- 839
0
votes
3
answers
143
views
Short Eratosthenes Sieve
I've written a short implementation of the Eratosthenes' sieve.
...
3
votes
2
answers
845
views
Sieve of Eratosthenes in Rust
This is a relatively simple implementation of the Sieve of Eratosthenes in Rust. The main objective is to find the \$n\$th prime quickly when \$n\$ might grow to huge numbers.
...
- 3,007
0
votes
2
answers
166
views
Prime number generation - SPOJ
This is a program to generate prime numbers for a given range. The sieve of Eratosthenes algorithm was implemented, but still the SPOJ says time limit exceeded. Where can some optimizations be made?
...
7
votes
2
answers
159
views
Prime number segmented sieve
I tried to solve the SPOJ prime number problem below. The code produced correct results, but Time limit exceeded and also memory need around 970M which is not efficient(?)
How can I optimize this ...
- 171
4
votes
1
answer
172
views
Sieve of Eratosthenes in Python
This is yet another take in Python for the infamous Sieve of Eratosthenes. I am a beginner in Python so any criticism is highly appreciated.
...
- 1,545
1
vote
0
answers
134
views
Get prime divisors of an Int32 using a wheel
I recently played around with prime factorization using a prime wheel. Much of the heavy lifting is done by the PrimeWheel class. I think the implementation is ...
- 5,522
2
votes
2
answers
3k
views
Find primes using Sieve of Eratosthenes with Python
I was Googling for a 'correct' or 'efficient' implementation of the Sieve of Eratosthenes. I found them all more complicated than what I came up with. I am by no means a Python expert, so I was ...
3
votes
1
answer
608
views
Functional Sieve of Eratosthenes in Clojure
For some reason, this is the first time I've ever written an implementation of the Sieve of Eratosthenes. I basically just stared at the Wikipedia walkthrough of the algorithm until it made sense, ...
- 16.1k
2
votes
2
answers
2k
views
Finding the size of the largest connected component in a graph
Given this question, which simply can be explained as follows:
Given the number of nodes and the number of edges in a graph, find the size of the largest connected component of the graph. If this ...
- 172
4
votes
4
answers
870
views
8
votes
1
answer
4k
views
Prime Number Generator in Swift
I would like to make (or improve my function) a function that returns an array of integers containing all the prime numbers from 2...n that can execute as quickly ...
- 271
4
votes
2
answers
326
views
Sieve of Eratosthenes for small limits
I coded a sieve of Eratosthenes, I think it's quite fast for small limits. Any suggestions how to improve it? Especially for small limits, say limits < 50,000,000. (Also coded a parallel sieve (in ...
- 141
6
votes
1
answer
210
views
Kotlin sieve using sequences
While learning about functional programming the simple sieve example was brought up in Haskell. I wanted to try a Kotlin implementation using sequences.
Are there any other quick wins without ...
- 161
8
votes
1
answer
2k
views
Finding nth Prime using Python and Sieve of Eratosthenes
I'm currently working through the Project Euler Problems using HackerRank to evaluate the code and I'm stuck on the 7th Problem.
...
- 405
5
votes
4
answers
664
views
Improved RandomGenerator with nextPrime() method
I am trying to implement a method that generates a random prime number between a given range.
I have tried using a simple method to find whether a number is prime or not, advanced simple method, ...
