Fib in C, Python, PyPy, R, and R (JIT)

fib.c

#include "assert.h"
#include "stdio.h"

unsigned long long int fib(int n) {
  assert(n >= 0);
  if (n < 2)
    return n;
  return fib(n - 1) + fib(n - 2);
}


int main(int argc, const char *argv[])
{
  int i;
  for (i = 0; i < 35; ++i) {
    printf("%llu\n", fib(i));
  }
  return 0;
}

fib.py

def fib(x):
  if x < 2:
    return x
  return fib(x - 1) + fib(x - 2)

for i in xrange(35):
  print i, fib(i)

fib.R

require(compiler)
enableJIT(3)

fib = function(x) {
  if (x < 2) {
    return(x)
  }
  return(fib(x - 1) + fib(x - 2))
}

for (i in 1:34) {
  print(i)
  print(fib(i))
}

results.md

R: 2 minutes 45 seconds
R (JIT): 1 minute 11 seconds
Python: 8.198 seconds
PyPy (Python JIT): 1.519 seconds
C: 0.151 seconds