Printing a receipt using parallel arrays c++ - c++

Question

I have been given this assignment for a lab project, and I have everything working until it gets to the receipt part. The issues I am having are 1) printing the incorrect menu items ordered, and 2) getting -42........ number for the pricing. I've looked through this several times and have spoken with others in the class. This is where we are ALL having issues. My TA said to use array[array1[counter]] for this section, but it doesn't seem to work. Can you help me focus on where things are seriously incorrect?
#include <iostream>
#include <iomanip>
#include <string>
using namespace std;
const int NUM_MENU_ITEMS = 10; // num items on the menu
const int MAX_ORDER_ITEMS = 5; // max num of items per order
const double DISCOUNT_MIN = 20.00; // min subtotal to get discount
const double DISCOUNT_RATE = 0.25; // disc rate for highest-priced item
// Menu: parallel constant arrays
const string menuItem[NUM_MENU_ITEMS] = {
"Burger", "Hot Dog", "Chicken Fingers", "Fries",
"Tots", "Tea", "Coke", "Diet Coke", "Water", "Cookies" };
const double menuPrice[NUM_MENU_ITEMS] = {
3.50, 2.75, 4.25, 2.50, 3.25,
1.00, 1.25, 1.25, 0.25, 2.50 };
int main()
{
// Order: parallel partial arrays of items ordered
// Each item has an item number, quantity ordered, and total price
// TODO: declare a list of item numbers
// TODO: declare a list of quantities
// TODO: declare a list of item prices (menu price X quantity)
// TODO: declare other variables as needed
double total, subtotal, discount;
// receipt line data
string recName;
int recQty;
int j = 0;
double recPrice;
// print menu
cout << "MENU:\n" << fixed << setprecision(2);
cout << "## Item Price\n";
cout << "-- --------------- -------\n";
// TODO: write a loop to print the menu
int i = 0;
int itemNumber[NUM_MENU_ITEMS] = {
0,1, 2, 3, 4, 5, 6, 7, 8, 9 };
while (i <= 9)
{
cout << setw(2) << itemNumber[i] << " " <<
left << setw(15) << menuItem[i] <<
right << " $ " << setw(5) << menuPrice[i] << endl;
i++;
}
cout << endl;
// get order
int counter = 0;
int itemQuantity[MAX_ORDER_ITEMS];
double itemPrice[MAX_ORDER_ITEMS];
int itemOrder[MAX_ORDER_ITEMS];
string itemName[MAX_ORDER_ITEMS];
do {
cout << "Enter quantity and menu item number (0 0 to end):\n";
cout << "Item 0: ";
cin >> itemQuantity[counter] >> itemOrder[counter];
itemOrder[counter] = itemNumber[counter];
itemPrice[counter] = menuPrice[itemOrder[counter]] *
itemQuantity[counter];
itemName[counter] = menuItem[itemOrder[counter]];
counter++;
} while (counter < MAX_ORDER_ITEMS && itemQuantity[counter] != 0);
// TODO: repeat inputs until quantity is 0 or MAX_ORDER_ITEMS exceeded
//{
// //TODO: add an item to the order parallel arrays
// cout << "Item " << menuItem[i] << ": ";
// cin >> itemQuantity[i] >> itemPrice[i];
//}
double maxItemPrice = 0;
for (i = 0; i < MAX_ORDER_ITEMS; i++)
{
if (itemPrice[counter] > maxItemPrice)
maxItemPrice = i;
}
// find the subtotal price
// TODO: use a loop to calculate the sum of all order prices
subtotal = 0;
for (i = 0; i < MAX_ORDER_ITEMS; i++)
{
subtotal = subtotal + itemPrice[counter];
}
// discount highest order line by 25% when total > $20
if (subtotal >= DISCOUNT_MIN)
{
// TODO: add a loop to find the maximum item price
discount = DISCOUNT_RATE * maxItemPrice;
}
else
discount = 0;
// calculate the total price
total = subtotal - discount;
// print the receipt
cout << "\n----------------------------\n";
cout << "Item Qty Price\n";
cout << "--------------- --- -------\n";
// TODO: use a loop to print the lines of the receipt
i = 0;
for (i = 0; i < MAX_ORDER_ITEMS; i++)
{
recName = itemName[i];
recQty = itemQuantity[i];
recPrice = itemPrice[menuPrice[i]];
cout << left << setw(15) << recName << " "
<< right << setw(3) << recQty << " $"
<< setw(6) << recPrice << endl;
}
cout << "\nSubtotal: $" << setw(6) << subtotal << endl;
cout << "Discount: $" << setw(6) << discount << endl;
cout << "Total Price: $" << setw(6) << total << endl << endl;
system("pause");
return 0;
}

Answer 1

In this line in the do while loop:
} while (counter < MAX_ORDER_ITEMS && itemQuantity[counter] != 0);
you have already incremented counter so your while loop is checking a part of the
itemQuantity
array that has not been input yet.
Also, here
double maxItemPrice = 0;
for (i = 0; i < MAX_ORDER_ITEMS; i++)
{
if (itemPrice[counter] > maxItemPrice)
maxItemPrice = i;
}
counter is a variable used previously and has not been updated. What is counter representing, and what is i?
And again here,
subtotal = 0;
for (i = 0; i < MAX_ORDER_ITEMS; i++)
{
subtotal = subtotal + itemPrice[counter];
}
Counter is still the same as it was left in the do while loop. Here it should be
subtotal = 0;
for (i = 0; i < MAX_ORDER_ITEMS; i++)
{
subtotal = subtotal + itemPrice[i];
}
Check array parameters closely and make sure what's written is doing what you want it to do. Best of luck!