#include<stdio.h>
#include<stdlib.h>

/* fibonacci number in scheme
 (define (fib n a b)     ; call with (fib n 1 1)
    (if (< n 3) b (fib (- n 1) b (+ a b))))
*/

int fib1(int n)
{
  if (n<3) return 1; else return fib1(n-1) + fib1(n-2);
}

int fib2(int n)
{
  int a = 1, b = 1;
  int temp;
  while (n>2)
    { temp = b;  
      b = a+b;  
      a = temp;  
      n--; 
    }
  return b;
}

// WHICH C FUNCTION HAS MORE IN COMMON WITH THE SCHEME VERSION?
int fib3(int n, int a, int b)   // a,b should be initially passed 1
{
  if (n<3) return b; else return fib3(n-1,b,a+b);
}

int main()
{
  printf(" %d  %d  %d\n", fib1(10), fib2(10), fib3(10,1,1));
  return 0;
}