C program to check whether a number is prime and to display Fibonacci series up to the given prime number

#include<stdio.h>

#include<conio.h>

void main()

{

 int num,flag=0,i,j,a=0,b=1,c;

clrscr();

printf("Enter the number:\n");

scannf("%d",&num);

if(num==1)

{

printf("1 is neither prime nor composite");

getch();

exit(0);

}

else

{

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

if(num%i==0)

flag++;

}

if(flag>0)

printf("Number is not prime");

else

{

printf("Number is prime\nFibonacci series is:\n%d\t%d\t",a,b);

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

{

c=a+b;

printf("%d\t",c);

a=b;

b=c;

}

}

getch();

}