Code:
/*
Name: MPrime Finder
Copyright: 2005
Author: Devon Taylor
Date: 13/10/05 22:07
Description: Uses high precision gmp library and lucas lehmers
determinant formula to find extremely large Mersenne Primes.
*/
#include <windows.h>
#include <fstream>
#include <iostream>
#include <stdlib.h>
#include <math.h>
#include <stdio.h>
#include <gmp.h> //Import needed includes
using namespace std;
int main(int argc, char* argv[]){ //Initiate program
cout<<"Program is making preparations, one moment...\n";
long int n_check;
long int co=0;
long int prime_t;
long int test_primes[500001];
mpz_t d1;
mpz_init_set_si(d1,1);
long int count1=0;
long int d11;
while(count1<500000){
mpz_nextprime(d1,d1);
d11 =mpz_get_si(d1);
test_primes[count1]=d11;
count1=count1+1;
}
long int input_low;
long int input_high; //Initiate Long Integer variables
long int color;
color = atoi(argv[1]); //Set color
HANDLE console; //Initiate console handle
console = GetStdHandle(STD_OUTPUT_HANDLE);
SetConsoleTextAttribute(console, 3);
cout<<"Program Created By Devon Taylor in 2005 \n";
SetConsoleTextAttribute(console, 6);
cout<<"Enter an odd # > 3 and < ten mill to start calc. at: "; //Ask for Lower Boundry
SetConsoleTextAttribute(console, 2);
cin>>input_low;
SetConsoleTextAttribute(console, 6);
cout<<"Enter an odd # > 3 and < ten mill to stop calc. at: "; //Ask for High Boundry
SetConsoleTextAttribute(console, 2);
cin>>input_high;
SetConsoleTextAttribute(console, 8);
cout<<"Calculating.........";
FILE *fp;
ofstream a_file ( "Mersenne_primes.txt", ios::app ); //Create stream for a file
fp = fopen("Mersenne_primes.txt", "a"); //Open the file
//Create file pointer
mpz_t test_prime2;
mpz_t p; //Initiate High Precision Variables
mpz_t b;
mpz_t c;
mpz_t dd;
mpz_t x;
mpz_t two;
mpz_t r;
mpz_t k;
mpz_t w;
mpz_t y;
mpz_t m;
mpz_t s;
mpz_t kr;
mpz_t test;
mpz_t one;
mpz_t zero;
mpz_t limit;
mpz_t count;
mpz_init(limit);
mpz_init(kr);
mpz_init2(m,10000000);
mpz_init2(y,10000000);
mpz_init(test_prime2);
mpz_init2(s,1000000000);
mpz_init(c);
mpz_init(r);
mpz_init_set_si(zero,0);
mpz_init_set_si(one,1);
mpz_set_si(s,4);
mpz_init_set_ui(dd,input_high);
mpz_init_set_si(p,input_low);
mpz_init_set_si(two,2);
mpz_init_set_ui(c,3);
mpz_init_set_si(w,2);
mpz_init_set_si(k,3);
mpz_init_set_si(b,3);
mpz_init_set_si(x,3);
mpz_init_set_si(test,3);
mpz_init_set_ui(count,1);
int a=2; //Initiate Variables //| //|
int mt;
int t;
int z;
int s_limit=mpz_cmp(p,dd);
int div_three;
int div_five;
int div_seven;
int h;
int l;
int cvd_prm;
int cvd_p;
int is_prime;
int s_check;
while (s_limit<0){ //While the program stays within its boundries
mpz_add_ui(p,p,2); //Add 2 to the Mersenne Prime Exponent
s_limit=mpz_cmp(p,dd); //Check to see if number is within boundries
t=0; //Set exit variable to 0
mpz_set_si(b,3); //Set b to 3
mpz_sqrt(c,p); //Divide the Prime Exponent by 3
while(t==0){ //While exit statement is not true
z=mpz_divisible_p(p,b); //Check if Prime Exponent is divisible by b
mpz_add_ui(b,b,2); //If not divisible add 2 to b and try again
mt=mpz_cmp(c,b); //See if b becomes greater than c
if (z>0){ //If p is ever divisible, break while statement
t=1; //Set exit statement to true
}
if(mt<0){ //If the Prime Exponent is proven to be prime
prime_t =mpz_get_si(p);
mpz_set_si(x,3);
l =mpz_get_si(p);
mpz_mul_2exp(y,one,l);
mpz_sub_ui(y,y,1);
mpz_set_si(c,500000);
co=0;
while(t==0 && co<500000){ //Test for divisibility of prime #'s under 500,000
mpz_set_ui(x,test_primes[co]);
co=co+1;
z=mpz_divisible_p(y,x);
h=mpz_cmp(c,x);
if(z>0){
t=1;
SetConsoleTextAttribute(console, 5);
cout<<"Testing- "<<l<<", ";
}
if(h<0){
SetConsoleTextAttribute(console, 5);
cout<<" Testing ";
gmp_printf("%Zd",p); //State what's being tested
cout<<", ";
cvd_prm =mpz_get_si(p); //Convert Prime Exponent to an integer
mpz_mul_2exp(m,one,cvd_prm); //Put 2 to the power of the Prime Exponent
mpz_sub_ui(m,m,1); //Subtract 1 from the Mersenne Number from above
mpz_set_si(s,4); //Set s to 4
mpz_sub_ui(limit,p,1); //Set limit for Lucas test
mpz_set_ui(count,1); //Start process count at 1
is_prime=mpz_cmp(limit,count); // Check if count is over limit
while(t==0){ //While exit statement is false
mpz_mul(s,s,s); //Multiply s to itself
mpz_sub_ui(s,s,2); //Subtract 2 from s
mpz_mod(s,s,m); //Get modulous from s and m
mpz_add_ui(count,count,1); //Add 1 to the count
is_prime=mpz_cmp(limit,count); //Check if count exceeds the limit
s_check=mpz_cmp(s,zero); //Compare s to zero
if(is_prime<0){ //If the limit is reached its not prime, exit
t=1;
}
if (s_check==0){ //If s is equal to zero then the number is a Mersenne Prime
cvd_p =mpz_get_si(p); //Convert p to cvd_p
mpz_mul_2exp(r,one,cvd_p); //Store the mersenne prime
mpz_sub_ui(r,r,cvd_p); //Subtract 1
mpz_out_str(fp,0,r); //Write the Prime to the file
a_file<<" & ";
a_file<<cvd_p;
a_file<<", ";
SetConsoleTextAttribute(console, 7);
gmp_printf("%Zd",p); //Print the prime_exp to the screen
cout<<" is a Mersenne Prime, ";
t=1; //Exit to test a new #
}
}
}
}
}
}
}
fclose(fp);
cout<<".....Finished Calculating......";
system("pause");
}
