Krishnamurthy Number Java

2025年5月5日 | 阅读 3 分钟

Krishnamurthy 数字 是 Java 中的另一个特殊数字。一个数字被称为Krishnamurthy，如果它所有数字的阶乘之和等于该数字。Krishnamurthy 数字也被称为Strong 数字。就像质数和阿姆斯特朗数一样，Krishnamurthy 数字也经常被面试官询问，但以其另一个名称，即Strong 数字。

以下是我们用于检查 Krishnamurthy 数字的步骤：

我们首先取一个数字。
然后我们找到数字的每个数字的阶乘。
我们将每个数字的阶乘相加，并将其存储在另一个变量中。
如果每个数字的阶乘之和与原始数字相同，则该数字是 Krishnamurthy 数字。

让我们以Krishnamurthy 数字为例。

Number = 145
= 1! + 4! + 5!
= 1 + ( 4 * 3 * 2 * 1 ) + ( 5 * 4 * 3 * 2 * 1 )
= 1 + 24 + 120
= 145

让我们实现一个程序来检查用户输入的数字是否是 Krishnamurthy 数字。

KrishnamurthyNumber.java

//import required classes and packages
import Java.util.*; 
import java.io.*; 
import java.util.Scanner;

//create KrishnamurthyNumber class to check whether the given number is a Krishnamurthy number or not
class KrishnamurthyNumber { 
	
	// create fact() method to calculate the factorial of the number 
	static int fact(int number) 
	{ 
		int f = 1; 
		while (number != 0) { 
			f = f * number; 
			number--; 
		} 
		return f; 
	} 

	// create checkNumber() method that returns true when it founds number krishnamurthy 
	static boolean checkNumber(int number) 
	{ 
		int sum = 0;	//initialize sum to 0 
		
		int tempNumber = number;	//create a copy of the original number 
		
		//perform operation until tempNumber will not equal to 0
		while (tempNumber != 0) { 
			// calculate the factorial of the last digit of the tempNumber and then add it to the sum
			sum = sum + fact(tempNumber % 10); 

			// replace the value of tempNumber by tempNumber/10 
			tempNumber = tempNumber / 10; 
		} 

		// Check whether the number is equal to the sum or not. If both are equal, number is krishnamurthy number
		if(sum == number)
			return true;
		else
			return false;
	} 

	// main() method start
	public static void main(String[] args) 
	{ 
		int n;	//initialize variable n
		
		//create scanner class object to read data from user
		Scanner sc = new Scanner(System.in);
		
		//custom message
		System.out.println("Enter any number:");
		
		//store user entered value into variable n
		n = sc.nextInt();
	   
		if (checkNumber(n)) 
			System.out.println(n + " is a krishnamurthy number"); 
		else
			System.out.println(n + "is not a krishnamurthy number"); 
	} 
}

输出

让我们再实现一个程序来获取给定范围内的所有 Krishnamurthy 数字。

FindAllKrishnamurthyNumber.java

//import required classes and packages
import java.util.*; 
import java.io.*; 
import java.util.Scanner;

//create FindAllKrishnamurthyNumber class to get all the Krishnamurthy number in a given range
class FindAllKrishnamurthyNumber
{
	//main() method start
	public static void main(String args[])
	{
		int range;
		
		//create scanner class object
		Scanner sc=new Scanner(System.in);
		
		//show custom message
		System.out.println("Enter the value of range");
		
		//store user entered value into variable range
		range = sc.nextInt();

		for(int i = 1; i <= range; i++)
			checkNumber(i);
	}

	// create fact() method to calculate the factorial of the number 
	static int fact(int number) 
	{ 
		int f = 1; 
		while (number != 0) { 
			f = f * number; 
			number--; 
		} 
		return f; 
	} 

	// create checkNumber() method to check krishnamurthy number
	static void checkNumber(int number) 
	{ 
		int sum = 0;	//initialize sum to 0 
		
		int tempNumber = number;	//create a copy of the original number 
		
		//perform operation until tempNumber will not equal to 0
		while (tempNumber != 0) { 
			// calculate the factorial of the last digit of the tempNumber and then add it to the sum
			sum = sum + fact(tempNumber % 10); 

			// replace the value of tempNumber by tempNumber/10 
			tempNumber = tempNumber / 10; 
		} 

		// Check whether the number is equal to the sum or not. If both are equal, the number is Krishnamurthy number
		if(sum == number)
			System.out.println(number + " is a krishnamurthy number"); 
	}
}

输出