Pronic Number Program in Java

Java Program to Check Pronic Number

import java.util.Scanner;

public class PronicNumber {
    public static boolean isPronic(int num) {
        for (int i = 0; i <= Math.sqrt(num); i++) {
            if (i * (i + 1) == num) {
                return true;
            }
        }
        return false;
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter a number: ");
        int number = scanner.nextInt();
        scanner.close();
        
        if (isPronic(number)) {
            System.out.println(number + " is a Pronic number.");
        } else {
            System.out.println(number + " is NOT a Pronic number.");
        }
    }
}

You can also try this code with Online Java Compiler

Run Code

Output

Enter a number: 6
6 is a Pronic number.

Pictorial Presentation

Below is a simple representation of Pronic numbers:

0 = 0 × 1
2 = 1 × 2
6 = 2 × 3
12 = 3 × 4
20 = 4 × 5

This pattern continues for all Pronic numbers.

Flowchart

Examples

Example 1: Checking Multiple Numbers

public class PronicExample {
    public static void main(String[] args) {
        int[] numbers = {0, 2, 6, 12, 20, 30, 42, 56};
        
        for (int num : numbers) {
            if (isPronic(num)) {
                System.out.println(num + " is a Pronic number.");
            } else {
                System.out.println(num + " is NOT a Pronic number.");
            }
        }
    }
    
    public static boolean isPronic(int num) {
        for (int i = 0; i <= Math.sqrt(num); i++) {
            if (i * (i + 1) == num) {
                return true;
            }
        }
        return false;
    }
}

You can also try this code with Online Java Compiler

Run Code

Output

0 is a Pronic number.
2 is a Pronic number.
6 is a Pronic number.
12 is a Pronic number.
20 is a Pronic number.
30 is NOT a Pronic number.
42 is a Pronic number.
56 is a Pronic number.

Example 2: Checking Pronic Numbers in a Range

public class PronicRange {
    public static void main(String[] args) {
        System.out.println("Pronic numbers from 1 to 100: ");
        for (int i = 0; i <= 10; i++) {
            System.out.print((i * (i + 1)) + " ");
        }
    }
}

You can also try this code with Online Java Compiler

Run Code

Output

Pronic numbers from 1 to 100:
0 2 6 12 20 30 42 56 72 90

Time and Space Complexity

Time Complexity

• The loop runs approximately √n times, making the time complexity O(√n).
   
• If we check a number in a range, it will take O(N√N).

Space Complexity

• We are using only a few variables, so the space complexity is O(1).

Frequently Asked Questions

What is a Pronic number?

A Pronic number is a number that is the product of two consecutive integers (n × (n + 1)).

How do you check if a number is Pronic in Java?

You can check by iterating from 0 to √n and verifying if i * (i + 1) == n.

What is the time complexity of checking a Pronic number?

The time complexity is O(√n) since we loop up to the square root of n.

Conclusion

In this article, we discussed on how to check if a number is a Pronic number in Java. A Pronic number (or rectangular number) is the product of two consecutive integers, represented as n × (n + 1). We implemented a  Java program to determine if a given number is Pronic. Understanding this concept helps in improving mathematical logic and problem-solving in Java programming.