الگوریتم غربال اراتستن در زبان c :

/* Prime Number Sieve in C: main->p1->p2->p3->p4->...->p99

*/

#include

FILE *user; FILE *fopen();

/* main program to generate successive integers greater than 1*/

main()

{ int integer=2;

user=fopen("/dev/tty","w");

/* /dev/tty is the users terminal.*/

fprintf(user, "Use CTRL/C to stop me....\n");

while (1) p(1,integer++);

/*WAS printf("%d\n", integer++);*/

}

/* C co-function to record a prime and sieve out its multiples from the input*/

/* i is the input and n an index distinguish successive p's*/

/* Each process initializes itself when i=0. */

p(n,i) int n,i; /*WAS main() */

{

static int prime100, integer100;

/* restart */ static int QS100;

/*debug fprintf(stderr,"p(%d,%d)QS=%d,prime=%d,int=%d,\n",n,i,QSn,primen,integern);*/

/*assuming static data initially =0*/

switch(QSn)

{case 0:goto Q0;case 1:goto Q1; }

Q0:

if(n==99)return;/*'p99' is the end of the chain/pipeline.*/

primen=i; /*WAS scanf("%d", &prime);*/

fprintf(user,"%d is prime number %d\n",primen,n);

while(1){

/* suspend; */

QSn=1; return; Q1: integern=i;

/*WAS scanf("%d", &integer);*/

if (integern % primen )

p(n+1, integern);/*WAS printf("%d\n",integer);*/

}

}

الگوریتم غربال اراتستن در زبان ++c :

// Prime Number Sieve in C++

// Each prime is an object of class Prime

// Notice that the class is developed in terms of what a Prime is held to

// be responsible for in the program.

#include

class Prime{

int p; //A Prime must remember its value

Prime *next; //A Prime must remember where the next prime is.

public:

// A Prime is responsible for making sure it is set up correctly

Prime() { cerr<<"New Prime not initialized\n"; exit(1); }

Prime(const int n) { p=n ; next=(Prime*)NULL; }

// A Prime is responsible for handling possible primes it is sent

void sent(const int n){

if(n%p)

if(next) next->sent(n);

else next=new Prime(n);

}



// A Prime is responsible for printing itself and its next prime (if any)

friend ostream& operator<<(ostream& s, const Prime n)

{ s<<(n.p);

if(n.next){ s<<" "<<(*(n.next));

}

return s;

}

}; // end class Prime

main()

{

Prime *first=new Prime(2);

for( int n=3; n<=100; n++,n++)

first->sent(n);

cout<<*first<<"\n";

}

همچنین ببینید

• اعداد اول
• اثبات‌های نامتناهی بودن اعداد اول
• الگوریتم

پیوندهای خارجی