Questions tagged [primes]
Primes or prime numbers are numbers which are divisible only by themselves and one, starting with 2, 3, 5, 7, 11.... They are commonly used in encryption and hashing algorithms.
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Function to find successive primes with sums of previous terms as divisiors
Is this a successful piece of code and an appropriate way to rephrase the mathematical notation? Currently it does not find pairs, so I wonder how to approach reasoning deductively about this problem ...
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Project Euler 10(Python) | Summation of Primes
This is my Python3 code which solved the 10th problem of Project Euler. I haven't passed the last 2 time limit test cases.
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Project Euler 60: Prime Pair Sets
Project Euler Prime Pair Sets:
The primes 3, 7, 109, and 673 are quite remarkable. By taking any two primes and concatenating them in any order the result will always be prime.
For example, taking 7 ...
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Find perfect and amicable numbers
I've been playing with perfect, amicable and social numbers lately, and created a class for investigating these. At present, it has functions to return the perfect and amicable numbers in a specified ...
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Miller-Rabin Primality Test in Python
I have the following implementation of the Miller-Rabin test in Python:
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Performance of Haskell prime sieve
I have this code, which is a pseudo-Sieve of Eratosthenes for generating primes:
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Hunting for the 100,001st prime in Rust
Most of my programming experience is in Python, but my first language was C, and I was intrigued by the combination which Rust offers: a streamlined syntax and no manual memory management, but with ...
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generate prime factors via wheel factorization
I want to factor random values of n that range from uint.MinValue to uint.MaxValue as ...
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Prime sieve in Rust
Using Sieve of Eratosthenes, I created a function that returns a vector of primes up to given limit.
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Make an image where pixels are colored if they are prime
This code creates a black-and-white image of variable size where the n-th pixel is white if n is a prime number and black if it isn't. It works, but I wonder if it is well written or if it could be ...
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Find factor pairs of an integer in Rust
I'm trying to efficiently generate all pairs of factors of a number n.
For example, when n=27, the factor pairs are (1, 27), (3, 9), (9, 3), (27, 1)
The order in which the pairs are found is not ...
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Strong Goldbach Conjecture with set implementation
I have devised my own version for a Goldbach verification project which uses sets to compare already sieved primes. My implementation also uses generators to "sieve a segment" since storing ...
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Prime factorization algorithm by using the multiprocessing module of Python
I may introduce a Python code of prime factorization which is from my personal project that I'm working on.
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Numpy segmented Sieve Of Eratosthenes
For the segmented Sieve Of Eratosthenes, I have devised the following code provided. And I understand that it is not the best implementation; However, it should be much quicker than what it is now. ...
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Find primes using Wilson's Theorem
The following code is an instantiation of wilson's theorem. It uses a simple factorial and division theorem to check for primality. My issue is with the performance of the code, and there are two most ...
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Möbius function using iterators for prime factors
While working on Project Euler, I have come across a few questions involving usage of the little omega function, big omega function, and Möbius function.
My prior code wrote factors into an array and ...
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Multithreaded segmented Sieve of Eratosthenes
I am fairly new to Rust and thought a good way to practice would be to write a multithreaded segmented Sieve of Eratosthenes. It performs ok (searches ten-billion numbers in about 11 seconds on my ...
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Euler's totient function for large numbers
I made this algorithm to compute Euler's totient function for large numbers. A sieve is used.
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Benchmarking an improved wheel sieve
I followed your answers for my last questions (1st 2nd) and I came up with these new versions of my codes but I face some difficulties to measure the efficiency of my code, I use chrono library to ...
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Prime sieve for large numbers
I state that I am not an expert and that certainly the code can be improved.
I made this prime number sieve to be able to handle large numbers.
The basic idea is to write a number p=r+bW*k where r is ...
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Find factors of a Mersenne number
On RosettaCode I found this C++ version of modPow (compute 2ᵖ mod n) to find the factors of a Mersenne number.
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Next level Improved Sieve of Eratosthenes
This is the next development for the Sieve of Eratosthenes algorithm, where all the multiples of 2,3 and 5 are eliminated, which will not take any memory or time.
As my last question Improved Sieve of ...
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Improved Sieve of Eratosthenes
How can I get to a perfect coding for this algorithm?
I made the mathematical theorem, which is a development of the Sieve of Eratosthenes algorithm. I might use some help in coding.
You can find the ...
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Project Euler #51: "Prime digit replacements" in Rust
Problem: https://projecteuler.net/problem=51
"Find the smallest prime which, by replacing part of the number (not necessarily adjacent digits) with the same digit, is part of an eight prime ...
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Fast way to compute a^d mod n
For a Miller-Rabin primality test I need a fast way to compute a^d mod n.
Where a is one of 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, ...
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Sieve of Atkin C#
I don't fully understand how to make the Sieve of Atkin faster than the most ancient sieve.
All implementations I found online where slower than the one I made, but still It isn't faster than ...
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Calculate the first largest factor of 600851475143
ٍProblem description:
The prime factors of 13195 are 5, 7, 13 and 29. Largest prime factor 13195 is 29.
What is the largest prime factor of the number 600851475143 ?
Prime Factor:
any of the prime ...
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Count SemiPrimes task from Codility
I'm trying to solve the following exercise from codility:
A prime is a positive integer X that has exactly two distinct
divisors: 1 and X. The first few prime integers are 2, 3, 5, 7, 11 and
13.
A ...
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Clojure Prime Numbers from 1 to 1000
I am a beginner to Clojure and I made a little script that prints out every prime number from 1 to 1000. Let me know if there are any improvements that I can make:
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A simple JavaScript function that does prime factorization
This is a simple JavaScript function that does prime factorization.
I wrote it on an Android phone with online editor (I don't have access to computers in night time):
Code:
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Find prime numbers
I wanted to create a program that lists all prime numbers to a given upper bound and that will also provide the amount of primes in the set. After many hours of trial and error I was able to solve it.
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Prime number generator in lisp
My implementation is based on the incremental prime sieve described on Wikipedia. I'm relatively new to lisp so I would appreciate any comments on my coding style or on the algorithm.
The below code ...
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calculating all prime numbers up to a given number
This program calculates all prime numbers up to n. However it runs pretty slowly.
I was wondering if there was any optimisations I could make.
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C code for discovering numbers with interesting/beautiful/symmetric properties
Below is a C code that generates 1000 random positive integers, for each number we check primality, palindromic property, and the square root of the sum of the digits. The purpose is to find/discover ...
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Factor 999999 numbers as fast as possible
My code finds the prime factorization of numbers, ordering the prime numbers from least to greatest.
It prints a list of 999999 prime factorizations (which can be changed if you edit the function call ...
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MIPS-32 assembly: Determine if n is prime
I'm new to assembly and I'm learning on my own, so I'd appreciate the feedback. My priorities are correctness (on all MIPS-32 with sllv) > speed > readability ...
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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 ...
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Prime numbers iterator
I am not familiar with iterators. I am confused with the traits approach and the traditional one. I don't know which one I should use in 2021.
I wrote a minimal ...
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Average prime number from array- Javascript
My mission is to solve this:
Write a function that will take an array of numbers, and will return the average of all numbers in the array that are prime number.
So far I wrote this:
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Generating prime numbers quickly in rust
I am attempting to re-implement a postponed sieve algorithm for generating prime numbers in Rust. I am able to make a solution that works, but I have to use a couple of ...
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Improving Project Euler code problem #10
So, I just finished Problem 10 on Project Euler, but it took about 3 to 4 minutes for my output to come out, due to bad coding, I guess, any suggestions on how could I optimize my code?
Question
The ...
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My prime number generation program in Python
So I did my own take (I wrote my own algorithm) for generating prime numbers from 1 to 1000.
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A function to find all the primes between two numbers whose reverse is also a prime and doesn't include palindrome, in JS
I am trying to solve a challenge in which I have to write a function that takes in two numbers as arguments and returns an array containing numbers between them which are prime and their reverse is ...
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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 ...
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Python – return list (or not?) of prime numbers between two numbers
I'm trying to learn how to write code well in Python. I've been tinkering with a function that will return a list of all prime numbers between the two parameters. This is the best I could come up with ...
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Count prime numbers whose rotations are all prime
This code solves Project Euler problem 35:
The number, 197, is called a circular prime because all rotations of the digits: 197, 971, and 719, are themselves prime. There are thirteen such primes ...
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Find the 10001st prime number
Project Euler 7: What is the 10 001st prime number?
I currently have this code:
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Python Prime Search Slower Optimization
I have these 2 version of code. Both are looking for all primes under a certain ceiling value.
The first is testing against the set of all odd numbers.
The second in testing against the set of all 6k-...
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Optimize TI-BASIC Prime Numbers Finder
I wrote a program to find all the prime numbers up to N on my TI-84, however, it is quite slow for any number above, like, 50. Are there any ways to optimize my ...
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