CSE1141 Computer Programming I Homework #4

    1) Write a program that calculates the invoice of each flat in an apartment building. Assume that there are N flats in a building and apartment heating is the central system. 30% of bill will be shared equally among the flats, the rest 70% will be shared according to the consumption of each flat.

Sample Calculation:

    • Suppose that an apartment building has 3 flats

    • Consumption of each flat (m3): 12.8, 23, 9.2

    • Total Bill: 320.40 TL

        o 30% of bill: 96.12 TL

        o 70% of bill: 224.28 TL

    • Then, the bill for each flat should be calculated as follows:

        o The bill for Flat #1: 32.04 + 63.80 = 95.83 TL

    o The bill for Flat #2: 32.04 + 114.63 = 146.67 TL o The bill for Flat #3: 32.04 + 45.85 = 77.89 TL

Your program must have the following methods:

    a) public static void main(String[] args)

        ◦ Main method will take the inputs from the user.

        ◦ Then, it will invoke the methods calculateTheInvoice() and printBills(), respectively.


    b) public static double[] calculateTheInvoice (double[] flats, double totalBill)

        ◦ You should calculate the bill of each flat based on the given sample calculation scenario.

        ◦ This method should take the following parameters:

    o A double array flats that indicates the consumption of each flat.

            o A double value totalBill that contains the total consumption of the whole apartment building.

        ◦ Then, the method should return a double array, which contains the calculated bill for each flat, to the main() method.


    c) public static void printBills (double[] bills)

        ◦ You should print the values to the console display.

        ◦ First input (N) is the number of flats in the apartment building. It is followed by N inputs for N flat consumption, and the last input is for the total bill.

            o Input Format: N C1 C2 C3 .. Cn TotalBill

    o Sample Input: 3 12.8 23 9.2 320.40


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CSE1141 – S’21 | HW#4


where,

N is the number of flats,

C1, C2, .. Cn are the consumptions of each flat, and TotalBill is the total bill for the apartment building.

    d) Sample Runs

        i) Sample Run 1 (Input: 3 12.8 23 9.2 320.40)

3 12.8 23 9.2 320.40 Flat #1: 95.83 Flat #2: 146.67 Flat #3: 77.89

        ii) Sample Run 2 (Input: 15 12 14.2 15.87 21.4 19 13 8.1 11 15.14 16 23.14 27 5.98 7.18 17 812.90)

15 12 14.2 15.87 21.4 19 13 8.1 11 15.14 16 23.14 27 5.98 7.18 17 812.90

Flat #1: 46.47

Flat #2: 52.0

Flat #3: 56.21

Flat #4: 70.13

Flat #5: 64.09

Flat #6: 48.98

Flat #7: 36.65

Flat #8: 43.95

Flat #9: 54.37

Flat #10: 56.54

Flat #11: 74.51

Flat #12: 84.23

Flat #13: 31.31

Flat #14: 34.33

Flat #15: 59.05

    iii) Sample Run 3 (Input: 5 44.02 0 17 21.01 7.56 210.82)

5 44.02 0 17 21.01 7.56 210.82

1.Flat: 85.15

2.Flat: 12.64

3.Flat: 40.65

4.Flat: 47.25

5.Flat: 25.1







 
CSE1141 – S’21 | HW#4


    2) Write a program that will determine whether or not it is valid per the Luhn formula. The Luhn algorithm is a simple checksum formula used to validate a variety of identification numbers, such as credit card numbers. The task is to check if a given string is valid.

Validating a Number:

    • Strings of length 1 or less are not valid.

    • Spaces are allowed in the input.

    • All other non-digit characters are not allowed.

Example 1: valid credit card number

Suppose that the following number is given as the input:

4539 1488 0343 6467

    • The first step of the Luhn algorithm is to double every second digit, starting from the right. We will be doubling

4_3_    1_8_    0_4_    6_6_

    • If doubling the number results in a number greater than 9 then subtract 9 from the product. The results for our example:

8569 2478 0383 3437

    • Then, calculate the sum all of the digits:

8+5+6+9+2+4+7+8+0+3+8+3+3+4+3+7 = 80

    • If the sum is evenly divisible by 10, then the number is valid.

80 is divisible by 10, and the quotient is 8 (even) Then, the given number is valid!

Example 2: invalid credit card number

Suppose that the following number is given as the input:

8273 1232 7352 0569

    • Double the second digits, starting from the right

7253 2262 5312 0539

    • Sum the digits

7+2+5+3+2+2+6+2+5+3+1+2+0+5+3+9 = 57

    • 57 is not evenly divisible by 10, so this number is not valid!

Your program must have the following methods:

    a) public static void main(String[] args)

        ◦ Main method will take the input from user.

        ◦ Then it will invoke the method validateNumber() and print the result.


    b) public static boolean validateNumber (String number)

        ◦ Check if a given number (String) is valid or not.

        ◦ Then, the method should return the result (boolean) to the main() method.



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    c) Sample Runs

        i) Sample Run 1

7634 78KS Invalid Input !

        ii) Sample Run 2

7789!

Invalid Input !

        iii) Sample Run 3

4539 1488 0343 6467 DNumber:4_3_1_8_0_4_6_6_ LNumber:8569247803833437 Number is Valid

        iv) Sample Run 4

8273 1232 7352 0569 DNumber:8_7_1_3_7_5_0_6_ LNumber:7253226253120539 Number is Invalid

        v) Sample Run 5

42 123 4598

DNumber:_2_2_4_9_

LNumber:441438598

Number is Invalid

    vi) Sample Run 6

3 89 23 1234 DNumber:_8_2_1_3_ LNumber:379432264 Number is Valid



















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CSE1141 – S’21 | HW#4


 
CSE1141 – S’21 | HW#4


    3) Write a program that takes an input letter and outputs it in a diamond shape. Given a letter, it prints a diamond starting with 'A', with the supplied letter at the widest point.

Your program should satisfy the following requirements:

    • The first row contains one 'A'.

    • The last row contains one 'A'.

    • All rows, except the first and last, have exactly two identical letters.

    • The diamond is horizontally symmetric.

    • The diamond is vertically symmetric.

    • The diamond has a square shape (width equals height).

    • The letters form a diamond shape.

    • The top half has the letters in ascending order.

    • The bottom half has the letters in descending order.



        a) Examples

In the following examples, spaces are indicated by character “.”.

    i) Example 1

Diamond for letter 'A':

A

    ii) Example 2

Diamond for letter 'C':

..A..

.B.B. C...C

.B.B.

..A..

    iii) Example 3

Diamond for letter 'E':

....A....

...B.B...

..C...C..

.D.....D. E.......E

.D.....D.

..C...C..

...B.B...

....A....






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CSE1141 – S’21 | HW#4


Your program must have the following methods:


    b) public static void main(String[] args)

            ▪ Main method will take the input letter from the user.

            ▪ Then, it will invoke the method constructDiamond().

            ▪ Lastly, it will invokethe method printDiamond().



    c) public static char[][] constructDiamond (char letter)

            ▪ This method should take a char letter and construct the diamond shape for the given letter in a two dimensional char array.

            ▪ The size of your two dimensional array is determined based on the given letter.

            ▪ This method should return the two dimensional array to the main() method.



    d) public static void printDiamond (char[][] diamond)

            ▪ This method should take a two dimensional char array and print the content of it.






        e) Sample Runs

    i) Sample Run 1

Enter a Letter: 7 Invalid Input !

    ii) Sample Run 2

Enter a Letter: * Invalid Input !

    iii) Sample Run 3

Enter a Letter: A A

    iv) Sample Run 4

Enter a Letter: C

..A..

.B.B. C...C

.B.B.

..A..




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    v) Sample Run 5

Enter a Letter: d

...A...

..B.B..

.C...C. D.....D

.C...C.

..B.B..

...A...



    vi) Sample Run 6

Enter a Letter: AC Invalid Input !
CSE1141 – S’21 | HW#4



















































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CSE1141 – S’21 | HW#4


IMPORTANT NOTES

    1) Only parts selected from the selected questions will be graded. So if you send only one program, you might get a grade of 0 based on our evaluation.

    2) Write a comment at the beginning of each program to explain the purpose of the program. Write your name and student ID as a comment. Include necessary comments to explain your actions.

    3) Select meaningful names for your variables.

    4) You are allowed to use the materials that you have learned in lectures and labs. Do not use the ones that you have not learned in the course.

    5) The outputs of your programs must be the same as the sample runs above.

    6) You should exactly print the outputs with 2 digits after the decimal point.

    7) Please be sure that your programs run properly on any computer.

    8) Since only selected parts will be graded, send a complete solution for the homework; otherwise, you may get a zero-grade based on our evaluation.

    9) Your program will be tested with an auto-grader. So, it should take the inputs exactly the same in the sample runs and it should print the outputs exactly the same in the sample runs. Otherwise, your program may fail.

    10) Your program should execute correctly for different test cases.

    11) You should not print any messages before input taking.

    12) Please do not write any package name at the beginning of your code.

    13) Please zip all your files into a single zip file using file naming convention StudentID_HW4.zip, e.g.,
150120123_HW4.zip. Your zip file should contain the followings:

        a) Java source code for Question 1 (HW4_Q1_StudentID.java)

        b) Java class file for Question 1 (HW4_Q1_StudentID.class

        c) Java source code for Question 2 (HW4_Q2_StudentID.java)

        d) Java class file for Question 2 (HW4_Q2_StudentID.class

        e) Java source code for Question 3 (HW4_Q3_StudentID.java)

        f) Java class file for Question 3 (HW4_Q3_StudentID.class

    14) Submit your zip file to http://ues.marmara.edu.tr before deadline.

    15) You are responsible for making sure you are turning in the right file, and that it is not corrupted in anyway. We will not allow resubmissions if you turn in the wrong file, even if you can prove that you have not modified the file after the deadline.

    16) Each student should submit his/her own homework. You can discuss with your peers about the homework, but you are not allowed to exchange codes or pseudocodes. This also applies to material found on the web. If some submitted homework assignments are found to be identical or suspected to be identical, all involved parties will get a grade of ZERO from all homework. You should submit your own work. In case of any forms of cheating or copying, both giver and receiver are equally culpable and suffer equal penalties. All types of plagiarism will result in FF grade from the course.

    17) No late submission will be accepted.






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