C Program to print Sum of Fibonacci Series upto 'n' Terms.

#include<stdio.h>

#include<conio.h>

main()

{

                int n,i,f1=1,f2=1,f3=0,sum=0;

                clrscr();

                printf("Enter the number of terms\n");

                scanf("%d",&n);

                sum=f1+f2;

                for(i=3;i<=n;i++)

                {

                                f3=f1+f2;

                                sum=sum+f3;

                                f1=f2;

                                f2=f3;

                }

                printf("\nSum of %d terms of Fibonacci series is : %d",n,sum);

}