Question

Zeller's congruence is an algorithm developed to calculate the day of the week. Write a program that prompts the user

to enter a year, month, day of month and it displays the name of the week.

Here is my source code. I need it broke down into a flowchart.

public static void main(String[] args) {
       //all variables are initialized to 0, because local variables require at least an initial value before use
       Scanner input = new Scanner(System.in); // creation of scanner object for user input
       int year = 0, month = 0; // variables for collecting user input
       int k = 0, j = 0, dayOfWeek = 0, dayOfMonth = 0;; // j = century, k = year of century
      
       System.out.println("**********Zeller's congruence**********\n");
       //System.out.println();
      
       System.out.print("Enter year: eg 2012: ");
       year = input.nextInt();
      
       System.out.print("Enter month: 1-12: ");
       month = input.nextInt();
       while (month > 12) {
           System.out.println("There are no more than 12 months in a year, try again");
           System.out.print("Enter month: 1-12: ");
           month = input.nextInt();
       }
      
       System.out.print("Enter the day of the month: 1-31: ");
       dayOfMonth = input.nextInt();
       while (dayOfMonth > 31) {
           System.out.println("There is never more than 31 days in a month, try again");
           System.out.print("Enter the day of the month: 1-31: ");
           dayOfMonth = input.nextInt();
       }
      
       k = year % 100;
       j = year / 100;
      
       if (month <= 2) {
           month += 12;
       }
      
       dayOfWeek = dayOfMonth + 26 * (month + 1) / 10 + k + k / 4 + j / 4 + 5 * j;
       dayOfWeek = dayOfWeek % 7;  
      
       if (dayOfWeek == 0) {
           System.out.print("Day of the week is Friday");
       }
       else if (dayOfWeek == 1) {
           System.out.print("Day of the week is Saturday");
       }
       else if (dayOfWeek == 2) {
           System.out.print("Day of the week is Sunday");
       }
       else if (dayOfWeek == 3) {
           System.out.print("Day of the week is Monday");
       }
       else if (dayOfWeek == 4) {
           System.out.print("Day of the week is Tuesday");
       }
       else if (dayOfWeek == 5) {
           System.out.print("Day of the week is Wednesday");
       }
       else if (dayOfWeek == 6) {
           System.out.print("Day of the week is Thursday");
       }
       input.close();
       System.out.println("\n");
       System.out.print("**********By Mohamed Diakite**********");
              

   }

}

Answer 1

//pls provide +ve rating,thanks!!

=====================================

import java.util.*;

import javax.lang.model.util.ElementScanner6;

class Main {

public static void main(String[] args) {

//System.out.println("Hello world!");

//all variables are initialized to 0, because local variables require at least an initial value before use

Scanner input = new Scanner(System.in); // creation of scanner object for user input

int year = 0, month = 0; // variables for collecting user input

int k = 0, j = 0, dayOfWeek = 0, dayOfMonth = 0;; // j = century, k = year of century

System.out.println("**********Zeller's congruence**********\n");

//System.out.println();

System.out.print("Enter year: eg 2012: ");

year = input.nextInt();

System.out.print("Enter month: 1-12: ");

month = input.nextInt();

while (month > 12) {

System.out.println("There are no more than 12 months in a year, try again");

System.out.print("Enter month: 1-12: ");

month = input.nextInt();

}

System.out.print("Enter the day of the month: 1-31: ");

dayOfMonth = input.nextInt();

while (dayOfMonth > 31) {

System.out.println("There is never more than 31 days in a month, try again");

System.out.print("Enter the day of the month: 1-31: ");

dayOfMonth = input.nextInt();

}

//I changed you code from here ,CHEGGEA

int X,Y,Z,W,A,B,C,D;

B=dayOfMonth;

D=year/100;;

C=year;

if(month == 1)

{

A = 11;

C -= 1;

}

else if (month ==2)

{

A = 12;

     C -= 1;

}

else

{

A=month-2;

}

//calculate W,X,Y,Z and R by using algorithm given

C%=100;

D=year/100;

W = (13 * A - 1) / 5;

X = C / 4;

Y = D / 4;

Z = W + X + Y + B + C - 2 * D;

dayOfWeek = Z % 7;

if (dayOfWeek < 0)

{

dayOfWeek += 7;

}

//Up to here, CHEGGEA

//commented your code below..CHEGGEA

/*k = year % 100;

j = year / 100;

if (month <= 2) {

month += 12;

}

dayOfWeek = dayOfMonth + 26 * (month + 1) / 10 + k + k / 4 + j / 4 + 5 * j;

dayOfWeek = dayOfWeek % 7; */

if (dayOfWeek == 0) {

System.out.print("Day of the week is Sunday");

}

else if (dayOfWeek == 1) {

System.out.print("Day of the week is Monday");

}

else if (dayOfWeek == 2) {

System.out.print("Day of the week is Tuesday");

}

else if (dayOfWeek == 3) {

System.out.print("Day of the week is Wednesday");

}

else if (dayOfWeek == 4) {

System.out.print("Day of the week is Thursday");

}

else if (dayOfWeek == 5) {

System.out.print("Day of the week is Friday");

}

else if (dayOfWeek == 6) {

System.out.print("Day of the week is Saturday");

}

input.close();

System.out.println("\n");

System.out.print("**********By Mohamed Diakite**********");

}

}

===================================

//output1

**********Zeller's congruence**********

Enter year: eg 2012: 2019
Enter month: 1-12: 2
Enter the day of the month: 1-31: 18
Day of the week is Monday

//output2

**********Zeller's congruence**********

Enter year: eg 2012: 2019
Enter month: 1-12: 3
Enter the day of the month: 1-31: 12
Day of the week is Tuesday

//output3

**********Zeller's congruence**********

Enter year: eg 2012: 2018
Enter month: 1-12: 30
There are no more than 12 months in a year, try again
Enter month: 1-12: 12
Enter the day of the month: 1-31: 30
Day of the week is Sunday

//output4

**********Zeller's congruence**********

Enter year: eg 2012: 2018
Enter month: 1-12: 1
Enter the day of the month: 1-31: 31
Day of the week is Wednesday