Question

for java using the loop

1. The department of History has just bought a new photocopier. Any person using the photocopier must enter an identification code. You have been asked to do the following:

• Write a program that determines whether identification codes typed by users of a photocopier are valid, and prints appropriate messages. If the identification code, which is a four-digit number, is correct your program computes the cost of copying according to the table below.
• Your program should prompt the user for an identification code, read it and determine whether it is valid. An identification code is valid if its rightmost digit is correct. A correct digit is equal to the remainder of the sum of the other three digits divided by 7. For example, a valid code that gives a correct digit is   7011. However, 9999 is not a valid code. 7011 is a valid code because (7+0+1)%7 = 1, which is equal to the rightmost digit of 7011. But 9999 is not a valid code because (9+9+9)%7 = 6, which is not equal to the rightmost digit of 9999.

Correct digits are assigned as follows:

Student: 1, 2   (means 1 or 2)

Teacher: 3, 4, 5

Secretary: 6

Others: 7, 8, 9

Number of pages	1 to 10	10 to 20	>20
Students	0.10 Dhs	20% off	40% off
Teachers	0.30 Dhs	30% off	40% off
Secretaries	0.20 Dhs	25% off	40% off
Others	0.60 Dhs	10% off	20% off

Answer 1

please do upvote.If you have any problem do comment and i shall be happy to help you.Thanks for using HomeworkLib.

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import java.util.Scanner;

public class PhotoCopier
{

   public static void main(String args[])
   {

       //get input

       while(true)
       {
           Scanner read=new Scanner(System.in);
           System.out.println("Enter identification code or stop(to end): ");
           String code=read.next();

           if(code.equalsIgnoreCase("stop"))
           {

               break;
           }
           int fourth_digit=isValid(code);

           if(fourth_digit!=-1)
           {
               System.out.println("Enter number of pages: ");
               int pageCount=read.nextInt();

               printCost(pageCount,fourth_digit);

           }
           else
           {

               System.out.println("invalid code");
           }
       }
   }

   private static void printCost(int pageCount,int fourth_digit) {
       // TODO Auto-generated method stub

       double cost=0;

       //calculate cost according to table
       switch(fourth_digit)
       {

       case 1
       : case 2:

           if(pageCount<=10 )
           {

               cost=pageCount*0.1;
           }
           else if(pageCount >10 && pageCount <=20)
           {

               cost=pageCount*0.1;

               cost=cost-((20/100)*cost);

           }
           else
           {

               cost=pageCount*0.1;

               cost=cost-((40/100)*cost);
           }

           break;

       case 3: case 4 : case 5:

           if(pageCount<=10 )
           {

               cost=pageCount*0.3;
           }
           else if(pageCount >10 && pageCount <=20)
           {

               cost=pageCount*0.3;

               cost=cost-((30/100)*cost);

           }
           else
           {

               cost=pageCount*0.3;

               cost=cost-((40/100)*cost);
           }
           break;

       case 6:

           if(pageCount<=10 )
           {

               cost=pageCount*0.2;
           }
           else if(pageCount >10 && pageCount <=20)
           {

               cost=pageCount*0.2;

               cost=cost-((25/100)*cost);

           }
           else
           {

               cost=pageCount*0.1;

               cost=cost-((40/100)*cost);
           }
           break;

       case 7: case 8: case 9:  

           if(pageCount<=10 )
           {

               cost=pageCount*0.6;
           }
           else if(pageCount >10 && pageCount <=20)
           {

               cost=pageCount*0.1;

               cost=cost-((10/100)*cost);

           }
           else
           {

               cost=pageCount*0.1;

               cost=cost-((20/100)*cost);
           }

           break;

       default:
           System.out.println("invalid page count");

           break;

       }

       System.out.printf("cost is %f",cost);
   }

   private static int isValid(String code) {
       // TODO Auto-generated method stub

       int first_digit,second_digit,third_digit,fourth_digit;

       //get digits from code
       first_digit=Character.getNumericValue(code.charAt(0));
       second_digit=Character.getNumericValue(code.charAt(1));
       third_digit=Character.getNumericValue(code.charAt(2));
       fourth_digit=Character.getNumericValue(code.charAt(3));

       int sum=first_digit+second_digit+third_digit;

       int remainder=sum%7;

       //if valid return fourth digit
       if(remainder==fourth_digit)
       {
           return fourth_digit;
       }

       return -1;//if not valid return -1
   }

}

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