Some of the first C++ code I ever wrote, as a freshman in College.

mainp3.cpp

#include <iostream>

using namespace std;

#define songsPerCd 12
#define totalCds 5

//this code creates an automatic 2d array
bool shoppingCart[totalCds][songsPerCd];

void enterStore(){
	cout << "Welcome to the buyTunes Music Store.\n";}

bool cdIsPurchased(int i){
		int j;
		int songsOffCd=0;
		for(j=0;j<songsPerCd;j++){
			if(shoppingCart[i][j]){songsOffCd++;}}
		return (songsOffCd==songsPerCd)?1:0;}

bool songIsPurchased(int cdChoice, int songChoice){
	return (shoppingCart[cdChoice-1][songChoice-1])?1:0;}

void exitStore(){
	cout << "You have purchased:\n";
	double totalPrice=0;
	for(int i=0;i<totalCds;i++){
		if(cdIsPurchased(i)){
			totalPrice+=9.98;	//add the price of each CD to the total
			cout << "\tCD #" << i+1 << " for $9.98\n";}		//tell them they have bought that CD
		else{	//otherwise, report each song on the CD they have bought
			for(int j=0;j<songsPerCd;j++){
				if(shoppingCart[i][j]==1){
					totalPrice+=.98;	//add the price of each song to the total
					cout << "\tCD #" << i+1 << ", song #" << j+1 << " for $0.98\n";}}}}
	cout << "Your total is: $" << totalPrice << "\n" <<
			"Thank you for shopping at the buyTunes Music Store.\n";}

void purchaseCD(int cdChoice){
	for(int i=0;i<songsPerCd;i++){
		shoppingCart[cdChoice-1][i]=1;}
	cout << "CD #" << cdChoice << " has been added to shopping cart.\n";}

void purchaseSong(int cdChoice,int songChoice){
	shoppingCart[cdChoice-1][songChoice-1]=1;
	cout << "CD #" << cdChoice << ", song #" << songChoice << " has been added to shopping cart.\n";}

int main(){
	char option;

	enterStore();
	do{	//primary loop
		option=' ';
		cout << "Command> ";
		cin >> option;
		
		if(option=='s'){	//if the user chooses s, go through the single song purchase
			int songChoice;
			int cdChoice;

			cout << "Purchase a single song from which CD? (1-" << totalCds << ")> ";
			cin >> cdChoice;
			if((cdChoice<1)||(cdChoice>totalCds)){	//start over if the CD number is invalid
				cout << "Invalid CD number entered.\n";
				continue;}
			if(cdIsPurchased(cdChoice)){	//start over if the CD has already been purchased
				cout << "You have already purchased that CD!\n";
				continue;}

			cout << "Which song from CD #" << cdChoice << "? (1-" << songsPerCd << ")> ";
			cin >> songChoice;
			if((cdChoice<1)||(cdChoice>songsPerCd)){
				cout << "Invalid song number entered.\n";
				continue;}
			if(songIsPurchased(cdChoice,songChoice)){	//start over if the CD has already been purchased
				cout << "You have already purchased that song!\n";
				continue;}

			purchaseSong(cdChoice,songChoice);}

		else if(option=='c'){	//if the user chooses c, go through the entire CD purchase
			int cdChoice;
			cout << "Purchase which CD? (1-" << totalCds << ")> ";
			cin >> cdChoice;
			if((cdChoice<1)||(cdChoice>totalCds)){
				cout << "Invalid CD number entered.\n";
				continue;}
			if(cdIsPurchased(cdChoice)){	//start over if the CD has already been purchased
				cout << "You have already purchased that CD!\n";
				continue;}

			purchaseCD(cdChoice);}
		else{
			cout << "Invalid option.\n";}}
	while(option!='q');	//keep in the "command>" loop until the user decides to quit
	exitStore();}