Write a C program to print prime pairs with distance <=3

Write  a program to print all possible pairs of prime numbers which are having distance 3 or less than 3  between them in a natural number line starting from 1 to given number N.

Example: prime pairs with distance <=3 – (2,3),  (2,5),  (3,5),  (5,7)

  (3,7), (5,11) are prime pairs with distance >3

Program:

#include<stdio.h>

main()

{

               int i,j,n,x=2,x1=3,x2=0,flag;

               printf("enter n value");

               scanf("%d",&n);

               printf("(%d,%d)\n",x,x1);

               for(i=4;i<=n;i++)

               {

                              flag=0;

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

                              {

                                             if(i%j == 0)

                                             {

                                                            flag=1;

                                                            break;

                                             }

                              }

                              if(flag == 0)

                              {

                                            

                                             x2=i;

                                             if(x2-x<=3)

                                                            printf("(%d,%d)\n",x,x2);

                                             if(x2-x1<=3)

                                                            printf("(%d,%d)\n",x1,x2);

                                             x=x1;

                                             x1=x2;

                              }

               }

}

              

Output: