recursive fibonacci code example

Example 1: fibonacii sequence code

# Program to display the Fibonacci sequence up to n-th term

nterms = int(input("How many terms? "))

# first two terms
n1, n2 = 0, 1
count = 0

# check if the number of terms is valid
if nterms <= 0:
   print("Please enter a positive integer")
elif nterms == 1:
   print("Fibonacci sequence upto",nterms,":")
   print(n1)
else:
   print("Fibonacci sequence:")
   while count < nterms:
       print(n1)
       nth = n1 + n2
       # update values
       n1 = n2
       n2 = nth
       count += 1

Example 2: recursive fibonacci scheme

(define (fib n)
    (cond
      ((= n 0) 0)
      ((= n 1) 1)
      (else
        (+ (fib (- n 1))
           (fib (- n 2))))))

Example 3: recursive fibonacci scheme

(define (fib2 n)
    (let loop
      ((m 0)
       (k 1)
       (count n))
      (if (= count 0)
        m
        (loop k (+ m k) (- count 1)))))