algorithmdata-structuresrecursionmutual-recursion

Practical examples of Mutual Recursion?

I was reading about mutual recursion.In almost all the materials,examples of it was problem to determine whether an integer is even or odd?

int is_even(unsigned int n)
{
    if (n==0) return 1;
    else return(is_odd(n-1));
}

int is_odd(unsigned int n)
{
    return (!iseven(n));
}

Obviously above problem can be solved in an easier manner using a modulus operator.

Other example was a problem to find out if a person is female or male.This can also be solved in easier manner without using recursion.

So is the mutual recursion just theoretical or is there anywhere i can use it to practically to make my solution simpler than using any other technique?

Could you please help me out by giving such an example?

Solution

  • Mutual recursion is not very common but it's useful sometimes. Parsing text with the "recursive descent" method is one practical setting where you can find it.

    http://en.m.wikipedia.org/wiki/Recursive_descent_parser