C Program To Check Whether The Given Number Is A Fibonacci Number Or Not

/* C Program To Check Whether The Given Number Is A Fibonacci Number Or Not */
#include<stdio.h>
#include<conio.h>
void main()
{
 int f1,f2,f3,next,num;
 printf("Enter the number to be determined:\n");
 scanf("%d", &num);
 if((num==0)||(num==1))
   printf("%d is a Fibonacci term",num);
 else
 {
   f1=0;
   f2=1;
   f3=f1+f2;
   while(f3<num)
   {
     f1=f2;
     f2=f3;
     f3=f1+f2;
   }
   if(f3==num)
     printf("%d is a Fibonacci term",num);
   else
     printf("%d is not a Fibonacci term",num);
 }

}

Out Put:

Enter the number to be determined:
13
13 is a Fibonacci term