Question

This is an assignment for a C++ introduction class. This module included if statements. If you have any questions please feel free to let me know!

{

In this module you learned about making decisions in C++ and how to combine decision making with the material from the first few modules to solve problems.

For this assignment, write a program that calculates a discount for buying certain quantities of coffee. Consider the following scenario:

A coffee company sells a pound of coffee for $12.99. Quantity discounts are given according to the table below.

Quantity	Discount
5-9	5%
10-19	10%
20-29	15%
30 or more	20%

Write a program that asks for the number of pounds purchased and computes the total cost of the purchase. Make sure the output formatting is appropriate for the values provided. Be sure to include comments throughout your code where appropriate.

Input validation: Decide how the program should handle an input of less than 0.

}

Answer 1

Code:

#include<iostream>
using namespace std;
int main()
{
   // this variable is used to store the number of coffee's ordered
   int coffee_quantity;
   // prompting the user to enter the coffee quantity
   cout<<"Enter the number of coffee's needed:";
   // reading the quantity
   cin>>coffee_quantity;
   // calculating the total price
   double coffee_price = coffee_quantity * 12.99;
   // if the coffee quantity is greater than or equal to 5 and less than or equal to 9, discount of 5 percent is applied on total price
   if(coffee_quantity >= 5 && coffee_quantity <=9)
   {
       coffee_price -= (coffee_price * 0.05);
   }
   // if the coffee quantity is greater than or equal to 10 and less than or equal to 19, discount of 10 percent is applied on total price  
   else if(coffee_quantity >= 10 && coffee_quantity <=19)
   {
       coffee_price -= (coffee_price * 0.10);
   }
   // if the coffee quantity is greater than or equal to 20 and less than or equal to 29, discount of 15 percent is applied on total price  
   else if(coffee_quantity >= 20 && coffee_quantity <=29)
   {
       coffee_price -= (coffee_price * 0.15);
   }
   // if the coffee quantity is greater than or equal to 30, discount of 20 percent is applied on total price  
   else if(coffee_quantity >= 30)
   {
       coffee_price -= (coffee_price * 0.20);
   }
  
   // If the entered coffee quantity is less than or equal to zero, let the user know that quantity must be positive
   if(coffee_quantity <= 0)
   {
       cout<<"The quantity of coffee's to be ordered must be greater than 0\n";
   }
   // Else print the coffee quantity and the total price  
   else
   {
       printf("Number of coffee's ordered:%d\n",coffee_quantity);
       printf("Total cost of the purchase: $%.2f\n",coffee_price);
   }
   return 0;
}

Sample Output: