Are there any example of Mutual recursion?

Question

Are there any examples for a recursive function that calls an other function which calls the first one too ?

Example :

function1()
{    
    //do something         


        

Answer 1

It's a bit contrived and not very efficient, but you could do this with a function to calculate Fibbonacci numbers as in:

fib2(n) { return fib(n-2); }

fib1(n) { return fib(n-1); }

fib(n)
{
  if (n>1)
    return fib1(n) + fib2(n);
  else
    return 1;
}

In this case its efficiency can be dramatically enhanced if the language supports memoization