Write a Java program to check sunny number or not. Any number (n) can be the sunny number if its successor or the following number (n + 1) is a perfect square. For instance, 23 is because its following number, 24 (23 + 1), is a perfect square of 4.
package NumPrograms; import java.util.Scanner; public class SunnyNumber1 { private static Scanner sc; public static void main(String[] args) { sc = new Scanner(System.in); System.out.print("Enter Number to Check for Sunny Number = "); int sNum = sc.nextInt(); if (perfectSquare(sNum + 1)) { System.out.println(sNum + " is a Sunny Number"); } else { System.out.println(sNum + " is Not a Sunny Number"); } } static boolean perfectSquare(double sNum) { double squareRoot = Math.sqrt(sNum); return ((squareRoot - Math.floor(squareRoot)) == 0); } }

This program accepts the start and end range and prints the sunny numbers between a range or 1 to N.
package NumPrograms; import java.util.Scanner; public class Example2 { private static Scanner sc; public static void main(String[] args) { sc = new Scanner(System.in); System.out.print("Enter Start and End Range = "); int start = sc.nextInt(); int end = sc.nextInt(); System.out.println("The List of Numbers from " + start + " to " + end); for(int i = start; i <= end; i++) { if (perfectSquare(i)) { System.out.print(i + " "); } } } static boolean perfectSquare(int sNum) { if(Math.sqrt(sNum + 1) % 1 == 0) { return true; } else { return false; } } }
Enter Start and End Range = 1 1000
The List of Numbers from 1 to 1000
3 8 15 24 35 48 63 80 99 120 143 168 195 224 255 288 323 360 399 440 483 528 575 624 675 728 783 840 899 960