Project $2$: Zeller's Algorithm

$($Zeller$.$java$)$

Write a Java program for Zeller's Algorithm, which can be used to determine the day of the week for any date

in the past, present, or future.

The program should request the user to enter the date values $($month$,$ day, and year$).$ Next, the program should

apply the algorithm $($see below$),$ and display the appropriate day of the week. The program should loop until the

user enters $0$ for a month. Use the pre$-$test while loop with a sentinel$-$value structure. See Listing $4\mathrm{.}6$ from

the textbook for an example of this type of structure. Do not use any exit, break, or boolean variable.

In addition, validate that the month is between $0$ and $12,$ and that day is between $1$ and $31.$ Use the while loop

structure for error checking. Do not use any other method or algorithm to solve this problem. See listing $4\mathrm{.}7$

for an example of this type of loop.

Algorithm:

The formula is:

$G=([2\mathrm{.}6M-\mathrm{.}2]+K+D+[\frac{D}{4}]+[\frac{C}{4}]-2C)mod7$

where:

M: is the month number

K : is the day of the month

C : is the century number

D : is the year number

explanations:

M: March is considered month $1$ and February is considered month $12.$ Therefore,

January and February are considered to be part of the previous year.

C: Is the first two digits of the year

D: Is the last two digits of the year

G : If this value is less than $0,$ add a value of $7$ to G

You need to cast the following expression as an integer: $[2\mathrm{.}6$ M$-\mathrm{.}2]$

examples:

Suggested Logic: ${?}_{(}())$

Display a Title

Get the month from the user

Validate the month

Get the day from the user

Validate the day

Get the year from the user

Calculate the day of the week

Convert M $($month$)$ to the correct value and changing the year is necessary

Convert the year to C and D

After setting up the values for M$,$ K$,$ C$,$ and D$,$ use Java operators to apply the formula

Get the value of G

Display the day of the week using a switch statement:

G is the day of the week where:

$0=$ Sunday $,1=$ Monday

$2=$ Tuesday

$3=$ Wednesday

$4=$ Thursday

$5=$ Friday

$6=$ Saturday Any other value: Display an error message.

Display the number of entries made by the user

Testing:

Test your final program for these values plus others including your own birth date:

Here is a sample output of this project:Enter month $($ or $0$ to exit$)$: $9$Enter year: $2003$Enter month $($ or $0$ to exit$)$: $2$Enter year: $2014$Enter month $($ or $0$ to exit$)$:$0$

Number of entries $=\}$

You should do this project in small steps. Please do not try to do everything at once...

Here is a possible plan:

Code and test the display of the Title

Then, ask the user to enter the month.

Set up the while loop with sentinel value $($month $0)$

Ask the user to enter the day and year

Add the counter

Display the counter $\frac{\frac{?}{?}}{?}$

After the above code works $($make sure that the user can enter several set of data, and exit with month $=0)$

Add the validations for month and day

Add the if and calculations statements for G

Display the value of G $($once you got the value right, then delete this statement$)$

Display the corresponding day of the week.

Skills demonstrated in this assignment

Comments $($Chapter $1)$

Constants and variables $($Chapter $2)$

Order of operations $($Chapter $2)$

Calculations $($Chapter $2)$

Operators $($Chapter $2)$

Reading input data $($Chapter $2)$

Importing Java Packages $($Chapter $3)$

If statements $($Chapter $4)$

Switch Statements $($Chapter $4)$

While loops $($Chapter $4)$

Grading

Comments and variable names $(5$ pts$)$

While with Sentinel Value $(8$ pts$)$

Error Checking for month $(5$ pts$)$

Error Checking for day $(5$ pts$)$

Calculation of Zeller's Algorithm $(20$ pts$)$

Calculation of M $(4$ pts$)$

Calculation of C $(3$ pts$)$

Calculation of D $(3$ pts$)$

Calculation of G $(10$ pts$)$

Determination of the day of the Week $(7$ pts$)$

Counting the number of entries $(5$ pts$)$

cant use break statements, exit breaks, booleans and test the code