How To Check Whether a Number is a Sunny Number or Not in Java?

What is Sunny Number?

A number is said to be a Sunny number if the square root of the next value of the given number is a perfect square of any number. For example, let's consider the number 3. If we take the number after 3, which is 4, and 2 is its perfect square root.

Here are some other examples of sunny numbers such as 3, 8, 15, 24, 35, 48, 63, etc.

Input & Output Scenarios

Following are some input and output scenarios that provide a better understanding of the sunny number:

Scenario 1

Suppose the given input number is 80:

Input: 80
Output: Yes

Calculation:
The next value of 80 = 80 + 1 = 81
The square root of 81 = 9

As we notice here 81 has a perfect square of 9, the 80 is a Sunny number.

Scenario 2

Suppose the given number is 47:

Input: 48
Output: No

Calculation:
The next value of 47 = 47 + 1 = 48
The square root of 48 = 6.92

Since the 48 has a no perfect square, the 48 is a not a Sunny number.

Let's see the program along with its output one by one.

Example 1

The following program checks whether the number 8 is a sunny number by determining if the next number 9, is a perfect square of any other number:

public class checkSunny{
   public static void main(String args[]){
      int inputNumber = 8;
      System.out.println("The given number is: " + inputNumber);
      //immidiate next of the original number
      double next = inputNumber + 1;
      
      //find the square root of the next number
      double square_root = Math.sqrt(next);
      
      //check whether the square root is a integer value or not
      if(((square_root - Math.floor(square_root)) == 0)){
         System.out.println("Yes! " + inputNumber + " is a sunny number.");
      }
      else{
         System.out.println("No! " + inputNumber + " is not a sunny number.");
      }
   }
}

Output

The above program produces the following output:

The given number is: 8
Yes! 8 is a sunny number.

Example 2

This is another example of how to check if a number is a sunny number. We define a method called checkSunnyNumber() that will check whether the number 14 is a sunny number by determining whether the next number, 15, is a perfect square of any integer:

public class checkSunny {

   //method to check for sunny number
   static boolean checkSunnyNumber(int inputNumber){

      //get the next value of given number
      double next = inputNumber + 1;
      double square_root = Math.sqrt(next);

      //check whether the square root is a integer value or not
      return ((square_root - Math.floor(square_root)) == 0);
   }
   public static void main(String args[]){
      int input_number = 14;
      System.out.println("The given number is: " + input_number);

      //calling the checkSunnyNumber() method to check the sunny number
      System.out.println("Is the number " + input_number + " is a sunny number? " + checkSunnyNumber(input_number));
   }
}

Output

Following is the output of the above program:

The given number is: 14
Is the number 14 is a sunny number? false