Program to generate Fibonacci series using the recursive and iterative method

C Programming Language / Recursion in c

679

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Program:

#include<stdio.h>
int fib(int n);
int TailRecursiveFib(int n);
int TRfib(int n, int next, int result);
int Ifib(int n);

main( )
{
	int nterms, i;
	printf("Enter number of terms : ");
	scanf("%d", &nterms);
	for(i=0; i<nterms; i++)
	printf("%d ", fib(i));
	printf("\n");

	for(i=0; i<nterms; i++)
	printf("%d ", TailRecursiveFib(i));
	printf("\n");
	Ifib(nterms);
	
	printf("\n");
}


/*Recursive*/
int fib(int n)
{
if(n==0 || n==1)
	return(1);
return(fib(n-1) + fib(n-2));
}

int TailRecursiveFib(int n)
{
	return TRfib(n,1,1);
}

int TRfib(int n, int next, int result)
{
	if(n == 0)
		return(result);
	return TRfib(n-1, next+result, next);
}


/*Iterative*/
int Ifib(int n)
{
	int i, x=0, y=1, z;
	printf("%d ", y);

	for(i=1; i<n; i++)
	{
	z=x+y;
	printf("%d ", z);
	x = y;
	y = z;
	}
}

Output:

Enter number of terms : 10
1 1 2 3 5 8 13 21 34 55
1 1 2 3 5 8 13 21 34 55
1 1 2 3 5 8 13 21 34 55
Press any key to continue . . .

Explanation:

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