Question

Design algorithms and solve problems incorporating the three control structures. For each program in this homework, develop flowcharts, then implement the design in Java. You do not need to include function calls in your flowchart diagrams.

Leap Year Detector

Design and implement a Java program that asks the user to enter a year, and then displays a message indicating whether that year is a leap year or not. Algorithm: if the year is evenly divisible by 4, it is a leap year.
Add a while or do-while loop to the program. Provide opportunities to the user to do it again.

Note the two examples below uses different approaches to decide whether or not the program should "do-it-again". Take integer 1 or 0 as the answer to whether or not repeat the program is easier. This approach would satisfy the homework requirements. You don't have to implement take 'y' or 'n' for the answer, but you are welcome to take the challenge!

Sample output example 1:

Enter a year I will tell you if it's a leap year:
2000
2000 is a leap year!
Do you wish to test another year? 1 for yes, 0 for no. Enter 1 or 0:
1
Enter a year I will tell you if it's a leap year:
2001
2001 is not a leap year!
Do you wish to test another year? 1 for yes, 0 for no. Enter 1 or 0:  
0
Thank you. Have a nice day!

Sample output example 2:  

Enter a year I will tell you if it's a leap year:
2000
2000 is a leap year!
Do you wish to test another year?
y
Enter a year I will tell you if it's a leap year:
2001
2001 is not a leap year!
Do you wish to test another year?   
n
Thank you. Have a nice day!

Answer 1

import java.util.Scanner;

public class LeapYear {
   public static void main(String[] args) {
       Scanner sc = new Scanner(System.in);
       int year,ch;
       while(true) {
           System.out.println("Enter a year I will tell you if it's a leap year: ");
           year=sc.nextInt();
           if(isLeap(year))
               System.out.println(year+" is a leap year!");
           else
               System.out.println(year+" is not a leap year!");

           System.out.println("Do you wish to test another year? 1 for yes, 0 for no. Enter 1 or 0: ");
           ch=sc.nextInt();
           if(ch==0)
               break;
       }
       System.out.println("Thank you. Have a nice day");
      
   }
   private static boolean isLeap(int year) {
       boolean leap = false;
       // if any year is divisable by 4 than there are many chances for leap year except few
       if (year % 4 == 0) {
           // if it is divisable by 100 than it shoud also divisable by 400 like 2000 etc
           if (year % 100 == 0) {
               // year is divisible by 400, so the year is a leap year
               if (year % 400 == 0)
                   leap = true;
               else
                   leap = false;
           } else
               leap = true;
       } else
           leap = false;
       return leap;
   }
}