/**************************
* bankAccount.cpp
* Section 4002 IC210
* 2 Oct 2009
* Compute the balance in a bank account after 5 years
*/
#include <iostream>

using namespace std;

//function prototypes

// transaction - does the interactive part for you 
//- taking the initial balance B 
//and returning the balance after the transaction.
double transaction(double B); 
//rate - returns the interest rate based on the account balance.
double rate(double B); 
//compound - gives the value of a single dollar 
//after a year's monthly compounding with annual interest rate r. 
double compound(double r); 

int main()
{
	//declare variables 
	double B,r;

	//initialize variables
	B = 0;

	//perform transactions and compute balance
	for(int i = 0; i< 5; i++)
	{
		B = transaction(B);
		r = rate(B);
		B = B*compound(r);
	}

	cout << "Balance after 5 years is " << B << endl;
	return 0;
}

// transaction - does the interactive part for you 
//- taking the initial balance B 
//and returning the balance after the transaction.
double transaction(double B)
{
	char type;

	cout << "Type of transaction ";
	cin >> type;

	double amount;
	cout << "amount? ";
	cin >> amount;

	//update
	if (type == 'w')
	{
		B = B - amount;
	}
	else
	{
		B = B + amount;
	}

	//return
	return B;
}

//rate - returns the interest rate based on the account balance.
double rate(double B)
{
	// Get # of thousands
	int T = B/1000;

	// Calc rate
	double r = 3 + T*0.5;
	if (r > 8)
		r = 8;

	return r;
}

double compound(double r)
{

	// Sim. year with monthly compounding
	double R = r/100, total = 1.0;

	for(int i = 0; i < 12; i++)
		total = total*(1 + R/12);

	return total;
}