README.md

My Scheme Practice

References

• https://www.scheme.org/
• https://en.wikipedia.org/wiki/Scheme_(programming_language)

<Note>

• Execute using Gauche 0.9.13 in JDoodle, unless otherwise specified

<List>

• Fibonacci Sequence (2024.12.29)

Fibonacci Sequence (2024.12.29)

• Generate the Fibonacci sequence using regular recursive, tail-recursive and botthom-up methods

• Code and Output

  Code : FibonacciSequence.scm

  ;; 1. Standard recursive method
  (define (fib-recursive n)
    "Compute the nth Fibonacci number using standard recursion."
    (if (<= n 2)
        1
        (+ (fib-recursive (- n 1)) (fib-recursive (- n 2)))))
  
  ;; 2. Tail recursive method
  (define (fib-tail-recursive n . args)
    "Compute the nth Fibonacci number using tail recursion."
    (let ((a (if (null? args) 1 (car args)))
          (b (if (or (null? args) (null? (cdr args))) 1 (cadr args))))
      (cond
        ((= n 1) a)
        ((= n 2) b)
        (else (fib-tail-recursive (- n 1) b (+ a b))))))
  
  ;; 3. Bottom-up method
  (define (fib-bottom-up n)
    "Compute the nth Fibonacci number using a bottom-up approach."
    (if (<= n 2)
        1
        (let loop ((a 1) (b 1) (count 2))
          (if (= count n)
              b
              (loop b (+ a b) (+ count 1))))))

  ;; Function to print Fibonacci sequences
  (define (print-fib-sequence name sequence)
    "Print a Fibonacci sequence with a given name."
    (display name)
    (display " : ")
    (display sequence)
    (newline))

  ;; Calculate and print the first 10 terms of the Fibonacci sequence using each method
  (print-fib-sequence "Standard Recursive Method"
                      (map fib-recursive (iota 10 1)))
  
  (print-fib-sequence "Tail Recursive Method    "
                      (map fib-tail-recursive (iota 10 1)))
  
  (print-fib-sequence "Bottom-up Method         "
                      (map fib-bottom-up (iota 10 1)))

  Output

  Standard Recursive Method : (1 1 2 3 5 8 13 21 34 55)
  Tail Recursive Method     : (1 1 2 3 5 8 13 21 34 55)
  Bottom-up Method          : (1 1 2 3 5 8 13 21 34 55)