Generate twin primes below 100.( (3,5), (5,7), ……………).

PROCEDURE:-

1.set n to 2

2.check the first prime

3.check the next prime by incrementing the n value

4. check the diff. of second prime to first prime (they are twin prime if the difference is 2)

6.repeat the process in steps 2 to  4 so as to generate all twin primes below 100  

CODE:-

#include<stdio.h>
void main( )
{
  /* n value is 2 because we are checking 1-100 twin primes, 1 is not prime,
       b can have any value initially,here it is 2, later on b value will be a value of  a*/
  int i,b=2,n=2,a,ctr;
 while(n<100)
 {
    ctr=0;   i=2;
     while(i<n)   /* logic for to check non prime numbers */
     {
       if(n%i = =0)
        {
     ctr=1; break;
        }
            i++;
    }
   if(ctr= =0)
    {
      a=n;           /* assining the value of n to a */
     if((a-b)= = 2)
        {
          printf(“( %d , %d) \n”,b,a);
         }
      b=a;  /* assining the value of a to b( it will assign only the prime no’s (i.e) the value of  a ) */
     }
   n++;
 }
}


Output:- (3,5) (5,7) (11,13)…………………