Write a program to print all two digit twin prime numbers?

Answer 1

#include

#include

void

main()

int prime(int n)

{

int i, j=n/2;

clrscr();

for(i=2; i<=j; i++)

{

if(n%j==0)

return 0;

}

return 1;

}

void

main()

{

int a,b,i;

clrscr();

printf("\n enter the twin prime numbers");

scanf("d",&a,&b);

printf("\n twin prime within this range \n");

if(a%2!==0)

i=a+1;

else;

i=a;

while(i+2<=b)

{

if(prime (i) &&prime(i+2) )

printf("\n%d\t%d",i,i+2);

i+1=2;

}

getch();

}

#include

#include

void main()

{

Int i, j, C;

printf("Enter the no");

Scanf("%d", &n);

for(j=2; j

{

If(n%j==0)

{

c++;

}

}

if(c==0)

{

printf(" Entered no is prime no");

}

getch();

}

Code example:

#include

#include

#include

void main()

{

int i,j;

clrscr();

for(i=3;i<=1000;i++)

{

for(j=2;j<=i;j++)

{

if(i%j==0)

break;

}

if(i==j)

cout<

}

getch(); // this is the easiest method for finding prime nos made by Taabi

}

B:

To write the c version: i.e not C++, you write: A: /****************************** * THIS IS THE EASIEST * METHOD OF GENERATING * PRIME NUMBERS USING C * MADE BY: githambo@gmail.com

*******************************/ #include #include int main() { int i,j,h,n; printf("Start:\a\n"); scanf("%d",&n); printf("End?\n\a"); scanf("%d",&h); for(in;i<h;i++) { for(j2;j<i;j++) { if(i%j0) break; }if(ij) printf("%d\t",j); } return 0; }

Answer 2

#include<iostream>

#include<cmath>

unsigned is_prime (const unsigned num) {

if (num<2) return false; // 0 and 1 are not prime

if ((num%2)==0) return num==2; // 2 is the only even prime

unsigned max_factor {(unsigned) sqrt ((double) num) + 1}; // test all odd factors >=3

for (unsigned factor {3}; factor<max; ++factor)

if ((num%factor)==0) return false;

return true; // the number is prime!

}

unsigned next_prime (unsigned num) {

while (!is_prime(++num));

return num;

}

int main() {

std::cout<<"2-digit Twin Primes\n\n";

unsigned a {2}, b {3};

while (b<100) {

if ((b-a)==2) std::cout<<"Prime twins: "<< a << " & " << b << '\n';

a=b;

b=next_prime (++b);

}

std::cout<<std::endl;

}