Functions!

[rantiv]

Hey so we are making a program and have to run it using srand(42). I am having trouble making my input repromt when they enter invalid input and not repromt the whole menu but just the selection.

Expected Output:
Welcome to the plinko simulator!

MENU: Please select one of the following options:

0 - Quit the program
1 - Drop a single chip into one slot
2 - Drop multiple chips into one slot
3 - Drop multiple chips into each slot

Enter your selection now:
INVALID SELECTION. Please enter 0, 1, 2 or 3
Enter your selection now:
INVALID SELECTION. Please enter 0, 1, 2 or 3
Enter your selection now:
INVALID SELECTION. Please enter 0, 1, 2 or 3
Enter your selection now:
INVALID SELECTION. Please enter 0, 1, 2 or 3
Enter your selection now:
GOODBYE!

my output:
Welcome to the plinko simulator!

MENU: Please select one of the following options:

0 - Quit the program
1 - Drop a single chip into one slot
2 - Drop multiple chips into one slot
3 - Drop multiple chips into each slot

Enter your selection now:
MENU: Please select one of the following options:

0 - Quit the program
1 - Drop a single chip into one slot
2 - Drop multiple chips into one slot
3 - Drop multiple chips into each slot

Enter your selection now:
INVALID SELECTION. Please enter 0, 1, 2 or 3
MENU: Please select one of the following options:

0 - Quit the program
1 - Drop a single chip into one slot
2 - Drop multiple chips into one slot
3 - Drop multiple chips into each slot

Enter your selection now:
MENU: Please select one o

#include <iostream>
#include <string>
#include <cmath>
#include <ctime>
#include <cstdlib>
#include <iomanip>
#include <stdlib.h>

using namespace std;

bool menuError(int menuChoice)
{
	if (menuChoice > 3 || menuChoice < 0)
	{
		cout << endl << "INVALID SELECTION.  Please enter 0, 1, 2, or 3" << endl << endl;

		return true;
	}

	else
	{
		return false;
	}
}
void rootMenu() {
      cout << "MENU: Please select one of the following options:" << endl << endl;
		cout << "0 - Quit the program" << endl;
		cout << "1 - Drop a single chip into one slot" << endl;
		cout << "2 - Drop multiple chips into one slot" << endl;
		cout << "3 - Drop multiple chips into each slot" << endl << endl;
		cout << "Enter your selection now: " << endl;
}

double ComputeWinnings(double location)
{
	double prize;
	const double PRIZE_0 = 100.00;
	const double PRIZE_1 = 500.00;
	const double PRIZE_2 = 1000.00;
	const double PRIZE_3 = 0.00;
	const double PRIZE_4 = 10000.00;
	const double PRIZE_5 = 0.00;
	const double PRIZE_6 = 1000.00;
	const double PRIZE_7 = 500.00;
	const double PRIZE_8 = 100.00;

	if (location == 0) { prize = PRIZE_0; }
	else if (location == 1) { prize = PRIZE_1; }
	else if (location == 2) { prize = PRIZE_2; }
	else if (location == 3) { prize = PRIZE_3; }
	else if (location == 4) { prize = PRIZE_4; }
	else if (location == 5) { prize = PRIZE_5; }
	else if (location == 6) { prize = PRIZE_6; }
	else if (location == 7) { prize = PRIZE_7; }
	else if (location == 8) { prize = PRIZE_8; }

	return prize;

}

double singleChip(int slotNumber, int chipNumber)
{
	double location = slotNumber;

	if (slotNumber >= 0 && slotNumber <= 8) 
	{
		for (int i = 0; i < 12; i++) 
		{

			double random = rand() % 2;
			if (random < 1)
			{
				location = location - 0.5;
			}
			else
			{
				location = location + 0.5;
			}
			if (location < 0)
			{
				location = 0.5;
			}
			else if (location > 8)
			{
				location = 7.5;
			}
		}


	}


	return location;
}

double multipleChips(int slotNumber, int chipNumber){
   double totalWinnings = 0;
	double location = slotNumber;

	if (chipNumber > 0)
	{
		if (slotNumber >= 0 && slotNumber <= 8)
		{

			for (int i = 0; i < chipNumber; i++)
			{ 
				location = singleChip(slotNumber, chipNumber);
				totalWinnings = totalWinnings + ComputeWinnings(location);
				//cout << location;
			}

		}
	}
   double average = totalWinnings / chipNumber;
	cout << "Total Winnings on " << chipNumber << " chips: " << totalWinnings << endl;
   cout << "Average winnings per chip: " << average << endl << endl;
	return location;
}

double allSlots(int slotNumber, int chipNumber)
{
	double location = slotNumber;
	double totalWinnings = 0;

	for (int i = 0; i <= 8; i++)
	{
		slotNumber = i;
		location = multipleChips(slotNumber, chipNumber);
		totalWinnings = totalWinnings + ComputeWinnings(location);

	}
	double average = totalWinnings / chipNumber;

	return location;
}
	
int main()
{
	double location = 0;
	int slotNumber = 0;
	int chipNumber = 0;
	int menuChoice;
	bool quit = false;
	srand(42);
	
   cout << "Welcome to the plinko simulator!" << endl << endl;
   cout << fixed << setprecision(2);
   do {
	   do {
		rootMenu();
		cin >> menuChoice;
      }
      while (menuError(menuChoice));
      if (menuChoice == 0)
		{
			cout << "GOODBYE!";
			quit = true;
		}
		else if (menuChoice == 1){
		  cout <<"*** DROP SINGLE CHIP ***" << endl << endl;
			chipNumber = 1;
			cout << "Which slot do you want to drop the chip(s) in (0-8)? " << endl;
			slotNumber = 0;
			cin >> slotNumber;

			if (slotNumber >= 0 && slotNumber <= 8)
			{
				location = singleChip(slotNumber, chipNumber);
				cout << "WINNINGS: $" << ComputeWinnings(location) << endl << endl;
			}
		}

		else if (menuChoice == 2)
		{
		   double totalWinnings = 0;
		   cout << "*** DROP MULTIPLE CHIPS ***" << endl << endl;
			cout << "How many chips do you want to drop (>0)? " << endl;
			cin >> chipNumber;
			if (chipNumber > 0)
			{
				cout << "Which slot do you want to drop the chip(s) in (0-8)? " << endl;
				slotNumber = 0;
				cin >> slotNumber;

				if (slotNumber >= 0 && slotNumber <= 8) //check this part again
				{
					location = multipleChips(slotNumber, chipNumber);
				}
			}
		}

		else if (menuChoice == 3)
		{
			cout << "How many chips do you want to drop (>0)? " << endl;
			cin >> chipNumber;
			cout << "*** SEQUENTIALLY DROP MULTIPLE CHIPS ***" << endl << endl;

			if (chipNumber > 0)
			{
				location = allSlots(slotNumber, chipNumber);
			}
		}

	}
	while (quit == false);
	
	return 0;
}