Solving The Leap Year Problem
The leap year problem is a common programming task that involves determining whether a given year is a leap year or not. In this article, we will explore the understanding, approach, step-by-step solution, and code to solve the leap year problem.
Understanding the Problem
A leap year is a year that is divisible by 4, except for end-of-century years (years ending in '00'), which are leap years only if they are also divisible by 400. For example, 2000 was a leap year because it is divisible by 400, whereas 1900 was not a leap year because although it is divisible by 4, it is also a century year not divisible by 400.
Approach
To solve the leap year problem, we can
Take the year as input.
Check if the year is divisible by 4.
If it is divisible by 4, check if it is a century year (ends with '00').
If it is a century year, check if it is divisible by 400.
If it meets all the conditions, it is a leap year; otherwise, it is not.
Let's implement this approach:
Step-by-Step Solution
Step 1: Accepting User Input
The code begins by importing the Scanner class from java.util package, which is used for taking input from the user.
The LeapYear class contains a main method, which is the entry point of the program. Inside the main method:
It creates a new Scanner object named scanner to read input from the console.
Asks the user to enter a year by displaying the message "Enter a year: ".
Reads the integer input provided by the user and stores it in the variable year.
Step 2: Determine if the input year is leap year or not
main method calls the isLeapYear method with the input year as an argument to check if it's a leap year or not.
The isLeapYear method takes an integer year as input and returns a boolean value (true if the year is a leap year, false otherwise).
It checks if the input year is divisible by 4 using the condition year % 4 == 0. If true, it proceeds to the next step.
If the year is divisible by 4, it checks if it's also divisible by 100 using the condition year % 100 == 0.
If true, it further checks if the year is divisible by 400 using the condition year % 400 == 0.
If all conditions (year % 4 == 0, year % 100 == 0, year % 400 == 0) are true, it returns true, indicating that the year is a leap year.
If the year is not divisible by 400, it returns false, indicating that the year is not a leap year.
If the year is not divisible by 4, the method directly returns false, indicating that the year is not a leap year.
Step 3: Prints the result
print the result based on the return value of isLeapYear.
Conclusion
In this article, we discussed the leap year problem, its conditions, and provided a step-by-step solution and code to determine whether a given year is a leap year or not. This problem is a good example of using conditional statements to solve a real-world problem.