A primality test is an algorithm for determining whether an input number is prime.
A primality test is an algorithm for determining whether an input number is prime.
Questions tagged [primality-test]
115 questions
4
votes
4 answers
Primality test using Fermat little theorem
code:
void prime()
{
int i,N;
scanf("%d",&N);
for(i=2;i
user2771151
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4
votes
3 answers
Can someone explain this Miller-Rabin Primality test pseudo-code in simple terms?
Here it is...
Input: n > 3, an odd integer to be tested for primality;
Input: k, a parameter that determines the accuracy of the test
Output: composite if n is composite, otherwise probably prime
Write n − 1 as (2^s)·d with d odd by factoring powers…
isados
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4
votes
2 answers
Turing Machine to accept strings of prime lengths
I have a homework problem that asks me to describe a program for a non deterministic Turing Machine that accepts L = {a^n: n is prime}. I'm not sure on how to go about this. do i know n? do i use the as as unary digits and count them? can i just…
calccrypto
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3
votes
1 answer
128 bit Miller Rabin Primality test
I wanted to implement Miller Rabin Primality Test for large numbers. I wanted to know how to deal with such huge numbers in C++. Should I write any special function to store and process those large numbers or care is taken automatically?
maddie
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3
votes
0 answers
Time complexity of Miller Rabin Primality Test
What would be the time complexity be for this algorithm below?
using ll = long long;
using u64 = ll;
using u128 = ll;
u64 binpower(u64 base, u64 e, u64 mod) {
u64 result = 1;
base %= mod;
while (e) {
if (e & 1)
…
Greg
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3
votes
2 answers
Implementing Miller-Rabin in C
I'm trying to implement the Miller-Rabin primality test in C99, but I'm coming across some problems getting it to work. I crafted a small test-set to verify whether or not the implementation works, here's how I'm checking for primes
int main() {
…
Bernardo Meurer
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3
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1 answer
How to implement the primality test algorithm from Wikipedia?
On Wikipedia the algorithm below is supposed to test if an odd integer, n, is a composite by the probabilistic Rabin-Miller primality test.
Input: n > 3, an odd integer to be tested for primality;
Input: k, a parameter that determines the accuracy…
Lehs
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3
votes
2 answers
Calculating whether number is prime in Prolog
I am trying to calculate if the input is a prime number but something goes wrong... here's my code:
primeNumber(X):-
prime_prime(A, 1).
prime_prime(A, B):-
R is A mod B,
R =:= 1,
R =:= A.
prime_prime(X, B):-
B < A,
Next is B…
Fjodor
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3
votes
1 answer
How do i improve the complexity of this randomized primality testing algorithm?
I wrote the following program which returns 1 if a number is prime and 0 if it is composite.
Though there's a possibility of falsely identifying a composite as prime .I want suggestions on improving(decreasing) the time complexity for the…
Namit Sinha
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3
votes
1 answer
Miller-Rabin Scheme implementation unpredictable output
I am new to Scheme. I have tried and implemented probabilistic variant of Rabin-Miller algorithm using PLT Scheme. I know it is probabilistic and all, but I am getting the wrong results most of the time. I have implemented the same thing using C,…
user270207
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3
votes
5 answers
Generating large prime numbers in python
I can't seem to make random prime numbers using this code, please can someone help me?
def RandomPrime():
prime = False
while prime == False:
n = random.randint(10000, 100000)
if n % 2 != 0:
for x in range(3, int(n**0.5), 2):
…
eulerstoastient
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3
votes
2 answers
Haskell prime number generator according to bits for very large numbers
I just got into haskell.
I'm trying to write a prime number generator that would return me a prime number depending on the number of bits I give it. Do I use some sort of Sieve of Eratosthenes? Would this be the quickest way? Currently, I already…
user805981
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3
votes
2 answers
Haskell Prime-testing confusion
So I'm totally new to Haskell, hope it doesn't show too much. By any means, I was trying to create a function to determine if a number is prime. The basic idea is this: Given a number, see if it is divisible by any other number less than it. If so,…
dj_bushido
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2
votes
1 answer
CUDA kernel for determining primes slower than OpenMP code - how can I optimize it?
To practice programming with CUDA in C++. I did an exercise which consists in displaying the prime numbers less than N. For each code I commented out the last display loop to compare only the calculation times.
The Makefile :
all: sum…
Monsieur AZERTY
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2
votes
1 answer
Time Complexity of this primality test function
What would be the time complexity of this function
bool prime(int n) {
if(n <= 1) {
return false;
} else if(n <= 3) {
return true;
} else if(n % 2 == 0 || n % 3 == 0) {
return false;
} else {
for(int i…
Greg
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