Fibonacci in different languages

fibonacci-fast.c

#include <stdio.h>

int fib(int n) {
  int twoBack = 0,
      oneBack = 1,
      nSoFar;

    for (nSoFar = 1; nSoFar < n; nSoFar++) {
      int oldOneBack = oneBack;
      oneBack += twoBack;
      twoBack = oldOneBack;
    }

    return oneBack;
}

int main() {
  printf("%d\n", fib(30));
}

fibonacci-fast.lisp

#!/usr/bin/env clisp

(defun fib (n)
  (fibIter n 1 0 1))

(defun fibIter (n nSoFar twoBack oneBack)
  (if
   (= n nSoFar) oneBack
   (fibIter n (+ nSoFar 1) oneBack (+ oneBack twoBack))))

(format t "~A~%" (fib 30))

fibonacci-fast.py

#!/usr/bin/env python

def fib(n):
    twoBack = 0
    oneBack = 1

    for nSoFar in range(1, n):
        oldOneBack = oneBack
        oneBack += twoBack
        twoBack = oldOneBack

    return oneBack

if __name__ == "__main__":
    print fib(30)

fibonacci.c

#include <stdio.h>

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

int main() {
  printf("%d\n", fib(30));
}

fibonacci.lisp

#!/usr/bin/env clisp

(defun fib (n)
  (cond
      ((= n 0) 0)
      ((= n 1) 1)
      (t (+ (fib (- n 1)) (fib (- n 2))))))

(format t "~A~%" (fib 30))

fibonacci.py

#!/usr/bin/env python

def fib(n):
    if n == 0:
        return 0
    elif n == 1:
        return 1
    else:
        return fib(n-1) + fib(n-2)

if __name__ == "__main__":
    print fib(30)

Language	Time
C	0.028
Fast C	0.002
Python	0.631
Fast Python	0.040
Lisp	2.828
Lisp Fast	0.036