pc-ip-13.c

Metadata

• Author — Amit Dutta
• Last updated — 05 Jan 2026
• License — MIT License (See the LICENSE file for details)

Problem Statement

Problem Statement

Question 13: Write a program to display the Fibonacci series using recursive function and iterative function.

Source Code

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#include <stdio.h>

long long int fib_rec(int);
void fib_rec_print(int);
void fib_ite_print(int);

int main()
{
    int n;
    printf("Enter the number of terms: ");
    scanf("%d", &n);
    fib_rec_print(n);
    fib_ite_print(n);
    return 0;
}

void fib_rec_print(int n)
{
    int i;
    printf("\nFibonacci Series (Recursion):");
    for (i = 0; i <= n; i++)
    {
        printf("  %lld", fib_rec(i));
    }
}

void fib_ite_print(int n)
{
    int i, t1 = 0, t2 = 1, t3;
    printf("\nFibonacci Series (iteration):");
    if (n > 0)
    {
        printf("  0");
    }
    if (n > 1)
    {
        printf("  1");
    }
    for (i = 2; i <= n; i++)
    {
        t3 = t1 + t2;
        printf("  %d", t3);
        t1 = t2;
        t2 = t3;
    }
}

long long int fib_rec(int n)
{
    if (n == 0 || n == 1)
    {
        return n;
    }
    else
    {
        return fib_rec(n - 1) + fib_rec(n - 2);
    }
}