Solution

/*

Programmer: Jennifer Leopold

Date: February 8, 2018

File: hw4.cpp

Purpose: Simulate a vending machine that sells snacks and

computes pounds user will lose by eating the

selected item based on user's metabolic rate.

To compile: fg++ hw4.cpp -o hw4

To execute: ./hw4

*/

#include <iostream>

using namespace std;

// Menu selections

const string MENU_ITEM_1 = "Dry Hay";

const string MENU_ITEM_2 = "Wet Hay";

const string MENU_ITEM_3 = "Kale";

const string MENU_ITEM_4 = "Ground Corn";

const string MENU_ITEM_5 = "Carrots";

const string MENU_ITEM_6 = "Carrots";

const string MENU_ITEM_7 = "Carrots";

const string MENU_ITEM_8 = "Industrially Milled Fortified "

"Sawdust Horse Feed";

const string MENU_ITEM_QUIT = "Quit";

const int NUM_MENU_ITEMS = 9;

// Price for each menu item

const float MENU_ITEM_1_PRICE = 1.5;

const float MENU_ITEM_2_PRICE = 1.25;

const float MENU_ITEM_3_PRICE = 0.75;

const float MENU_ITEM_4_PRICE = 2.5;

const float MENU_ITEM_5_PRICE = 1;

const float MENU_ITEM_6_PRICE = 1;

const float MENU_ITEM_7_PRICE = 1;

const float MENU_ITEM_8_PRICE = 0.5;

// Metabolic weight loss multiplying factor for each item

const int MENU_ITEM_1_WEIGHT_LOSS_FACTOR = 34;

const int MENU_ITEM_2_WEIGHT_LOSS_FACTOR = 33;

const int MENU_ITEM_3_WEIGHT_LOSS_FACTOR = 26;

const int MENU_ITEM_4_WEIGHT_LOSS_FACTOR = 12;

const int MENU_ITEM_5_WEIGHT_LOSS_FACTOR = 25;

const int MENU_ITEM_6_WEIGHT_LOSS_FACTOR = 25;

const int MENU_ITEM_7_WEIGHT_LOSS_FACTOR = 25;

const int MENU_ITEM_8_WEIGHT_LOSS_FACTOR = 13;

// Valid range for user's metabolic rate

const float METABOLIC_RATE_LOW = 0.05;

const float METABOLIC_RATE_HIGH = 0.09;

int main()

{

float metabolicRate; // user's metabolic rate

bool validInput; // true if input is valid

int menuChoice; // user's vending machine choice

bool isTimeToQuit = false; // true when user wants to quit

string selectedItemName; // chosen vending item name

float amtOwed; // amt owed for vending item

float amountRendered; // amt paid by user

float weightLoss; // # lbs lost for item eaten

// Greet user

cout << "\nWelcome to the Healthy Living "

<< "Vending Machine!\n\n";

// Get input for user's metabolic rate

do

{

cout << "Enter your metabolic rate ("

<< METABOLIC_RATE_LOW << "-"

<< METABOLIC_RATE_HIGH << "): ";

cin >> metabolicRate;

validInput = (metabolicRate >= METABOLIC_RATE_LOW) &&

(metabolicRate <= METABOLIC_RATE_HIGH);

if (! validInput)

cout << "Invalid input!\n";

} while (! validInput);

// Set precision to 2 decimal places for numeric outputs

cout.setf(ios::fixed);

cout.setf(ios::showpoint);

cout.precision(2);

// Let user repeatedly make selections from the vending

// machine until s/he chooses to 'quit'

do

{

// Display choices

cout << "\nHere's what we have for you today:\n";

cout << " 1. " << MENU_ITEM_1 << "\t\t$"

<< MENU_ITEM_1_PRICE << "\t("

<< MENU_ITEM_1_WEIGHT_LOSS_FACTOR << ")" << endl;

cout << " 2. " << MENU_ITEM_2 << "\t\t$"

<< MENU_ITEM_2_PRICE << "\t("

<< MENU_ITEM_2_WEIGHT_LOSS_FACTOR << ")" << endl;

cout << " 3. " << MENU_ITEM_3 << "\t\t$"

<< MENU_ITEM_3_PRICE << "\t("

<< MENU_ITEM_3_WEIGHT_LOSS_FACTOR << ")" << endl;

cout << " 4. " << MENU_ITEM_4 << "\t$"

<< MENU_ITEM_4_PRICE << "\t("

<< MENU_ITEM_4_WEIGHT_LOSS_FACTOR << ")" << endl;

cout << " 5. " << MENU_ITEM_5 << "\t\t$"

<< MENU_ITEM_5_PRICE << "\t("

<< MENU_ITEM_5_WEIGHT_LOSS_FACTOR << ")" << endl;

cout << " 6. " << MENU_ITEM_6 << "\t\t$"

<< MENU_ITEM_6_PRICE << "\t("

<< MENU_ITEM_6_WEIGHT_LOSS_FACTOR << ")" << endl;

cout << " 7. " << MENU_ITEM_7 << "\t\t$"

<< MENU_ITEM_7_PRICE << "\t("

<< MENU_ITEM_7_WEIGHT_LOSS_FACTOR << ")" << endl;

cout << " 8. " << MENU_ITEM_8 << " $"

<< MENU_ITEM_8_PRICE << "\t("

<< MENU_ITEM_8_WEIGHT_LOSS_FACTOR << ")" << endl;

cout << " 9. " << MENU_ITEM_QUIT << endl;

// Get selection; determine amount owed and lbs user

// will lose from eating this item

do

{

cout << "Please make a selection (1-"

<< NUM_MENU_ITEMS << "): ";

cin >> menuChoice;

validInput = (menuChoice >= 1) &&

(menuChoice <= NUM_MENU_ITEMS);

if (! validInput)

cout << "Invalid selection!\n";

} while (! validInput);

// Determine amount owed and # lbs user will lose

switch (menuChoice)

{

case 1: amtOwed = MENU_ITEM_1_PRICE;

weightLoss = MENU_ITEM_1_WEIGHT_LOSS_FACTOR *

metabolicRate;

selectedItemName = MENU_ITEM_1;

break;

case 2: amtOwed = MENU_ITEM_2_PRICE;

weightLoss = MENU_ITEM_2_WEIGHT_LOSS_FACTOR *

metabolicRate;

selectedItemName = MENU_ITEM_2;

break;

case 3: amtOwed = MENU_ITEM_3_PRICE;

weightLoss = MENU_ITEM_3_WEIGHT_LOSS_FACTOR *

metabolicRate;

selectedItemName = MENU_ITEM_3;

break;

case 4: amtOwed = MENU_ITEM_4_PRICE;

weightLoss = MENU_ITEM_4_WEIGHT_LOSS_FACTOR *

metabolicRate;

selectedItemName = MENU_ITEM_4;

break;

case 5: // Items 5-7 are all the same

case 6:

case 7: amtOwed = MENU_ITEM_7_PRICE;

weightLoss = MENU_ITEM_7_WEIGHT_LOSS_FACTOR *

metabolicRate;

selectedItemName = MENU_ITEM_7;

break;

case 8: amtOwed = MENU_ITEM_8_PRICE;

weightLoss = MENU_ITEM_8_WEIGHT_LOSS_FACTOR *

metabolicRate;

selectedItemName = MENU_ITEM_8;

break;

case 9: isTimeToQuit = true;

}

if (!isTimeToQuit)

{

// Prompt user for payment, and then output change

// and info about weight loss

cout << "\nYou chose " << selectedItemName << "...\n";

do

{

cout << "\nPlease deposit $" << amtOwed << ": ";

cin >> amountRendered;

validInput = amountRendered >= amtOwed;

if (! validInput)

cout << "Umm, that isn't enough!\n";

} while (!validInput);

cout << "Your change is $"

<< (amountRendered - amtOwed) << endl;

cout << "BTW, by eating " << selectedItemName

<< ", you will lose " << weightLoss << " lbs!\n";

}

} while (! isTimeToQuit);

// Sign off

cout << "\nStay healthy my friend!\n";

return 0;

}