My first program..

/*This is just a upgrading routine that I could use for a game that needs the person to upgrade their ship or a unit. Could possibly be used with an If statement to determine if the unit's experience is high enough to be ready for an upgrade./././*/#include <iostream>#include <cstdlib>#include <ctime>using namespace std;int main(){	srand(time(0)); 		int aliensKilled = rand() % 20 + 1;	int multi = rand() % 5 +1;	int score = aliensKilled * multi; //Determines if they have enough resources to upgrade..	cout << "Kills: " << aliensKilled << endl;	cout << "Resources: " << score << endl;	char choice;	int resources = score;			enum ship {FIGHTER = 25, BOMBER = 50, CRUISER = 100, DESTROYER = 200};	ship myShip = BOMBER;		do	{				if (resources < (CRUISER - myShip))		{			cout << "\n\nYou do not have enough resources.";			cout << "\n\n\nPress the enter key to exit.";			cin.ignore(cin.rdbuf()->in_avail() + 1);		} 		else		{			cout << "\nDo you want to upgrade your Bomber to a Cruiser for " 				<< (CRUISER - myShip) << " resource points?";						cin >> choice;						int newResource;			switch (choice) //Choosing yes or no..			{			case 'y': //If the choice is yes..				if (resources >= (CRUISER - myShip))				{					newResource = ((score) - (CRUISER - myShip));					cout << "\n\nYou have upgraded to a Cruiser. \nYou now have " <<						newResource << " resource points.";					cout << "\n\You now have a Cruiser.";					cout << "\n\n\nPress the enter key to exit.";					cin.ignore(cin.rdbuf()->in_avail() + 1);					cin.ignore(cin.rdbuf()->in_avail() + 1);				}				break;							case 'n': //If choice is no..				cout << "\nYou choose not to upgrade at this time.";				cout << "\nYou are left with a Bomber.";				cout << "\n\n\nPress the enter key to exit.";				cin.ignore(cin.rdbuf()->in_avail() + 1);				cin.ignore(cin.rdbuf()->in_avail() + 1);				break;							default:				cout << "\n\nYou must choose yes or no. (y/n)";			}		}	}while(choice != 'y' && choice != 'n');		return 0;}