// Dick.	cs201/lab/04
// Date Sun Apr 23 11:31:41 PDT 1995
// Teaching how functions work

/* 
This program shows you how a functions work in expressions.
To do this it has special tracing commands that report
what it is doing.  These command use 
the special diagnostic output channel "cout".

It also shows that you don't have to store a value before printing it.

*/

#include <iostream>
using namespace std;


//--------------------------------

int odd(int n) //returns 1 if n is odd and 0 otherwise
{
	cout<<"\n\tEntering 'odd' with n equal to "<<n<<endl;

	cout<<"\n\tReturning "<< n%2<<" to caller."<<endl;
	return n%2;
}

//--------------------------------

int half(int n)//returns half of n (rounded down)
{
	cout<<"\n\tEntering 'half' with n equal to "<<n<<endl;
	cout<<"\n\tReturning "<< n/2<<" to caller."<<endl;
	return n/2;
}

//--------------------------------

int dubl(int n)
{
	cout<<"\n\tEntering 'dubl' with n equal to "<<n<<endl;
	cout<<"\n\tReturning "<< n+n<<" to caller."<<endl;
	return n+n;
}

//--------------------------------

int trbl(int n)
{
	cout<<"\n\tEntering 'trbl' with n equal to "<<n<<endl;
	cout<<"\n\tReturning "<< dubl(n)+n<<" to caller."<<endl;
	return dubl(n)+n;
}

//--------------------------------

int next(int n)
{
	cout<<"\n\tEntering 'next' with n equal to "<<n<<endl;
	cout<<"\n\tReturning "<< n+1<<" to caller."<<endl;
	return n+1;
}

int main( ) 
{ 
	cout<<"4 * 2 ="<<dubl(dubl(2))<<endl;

	cout<<"6 * 2 ="<<trbl(dubl(2))<<endl;

	cout<< "odd(half(dubl(next(0)))) is " <<odd(half(dubl(next(0)))) <<endl;
}
//Exercise  Put the comment symbol '//' infront 
//			of  all the 'cout<<' statements
//	What happens when you compile and run the result?
//	Why do you add cout<< statements and then comment them out?