Program to print sum of the series S=1+x+x2+x3+…………+xn

PROGRAM

WAP to find  sum of the series S=1+x+x²+x³+…………+xⁿ

/**

 * class sumseries finds sum of the series.

 * This program dosn't use built-in method pow().

 * @author: Nitendra Verma 

 * @version: June 8,2013

 */

import java.util.Scanner;

public class sumseries

{

    int num,limit;     //instance variables

    public sumseries() //default constructor, initializes both variables to 0 

    {

        num=0;

        limit=0;

    } 

    public void getlimit(int n,int l) //method, assigns parameter values to variables 

    {

        num=n;

        limit=l;

    }

    

    public int findpow(int x,int p)  //method, returns power value of number

    {

    int value=1;

        for(int i=0;i<p;i++)

        {

            value*=x;

        }

        return value;   //returning value

    }

    

    public void findsumseries()  //method, finds sum of the series

    {

        int sum=0;

        for(int i=0;i<limit;i++)

        {

            sum+=findpow(num,i);

        }

        System.out.println("Sum of the series= "+sum);

    }

    

    public static void main()

    {

        sumseries ob=new sumseries();   //creating object of class sumseries

        Scanner in=new Scanner(System.in);  //creating object of class Scanner

        System.out.println("Enetr the number");

        int num=in.nextInt();               //inputting value

        System.out.println("Enetr the limit");

        int limit=in.nextInt();             //inputting value

        ob.getlimit(num,limit);             //calling method

        ob.findsumseries();                 //calling method

    }

}

OUTPUT:

Enetr the number

3

Enetr the limit

3

Sum of the series= 13

/*---------------Program developed by: Nitendra Verma---------------*/

//For more details visit http://javawithnitendra.blogspot.in

Program to check whether a number is Magic Number or not

PROGRAM

A Magic Number is a number in which the eventual sum of digits of the number is equal to 1.

For example,       172=1+7+2=10

                                 10=1+0=1

then 172 is a Magic Number.

 Design a class Magic to check if a given number is a magic number. Some of the members of the class are given below:

Class Name                        :               Magic  

Data members/instance variables  :

n                                             : stores the number

Member functions :

Magic()                                 : constructor to assign 0 to n

void getnum(int nn)       : to assign the parameter value to the number, n=nn

int Sum_of_digits(int)    : returns the sum of the digits of a number

void ismagic()                    : checks if the given number is a magic number by calling the function   

                                                  Sum_of_digits(int) and display appropriate message.

Specify the class Magic giving details of the constructor, void getnum(int), int Sum_of_digits(int) and void ismagic(). You do not need to write the main function.

/**
 * class magicnum checks whether a number is Magic Number or not. 
 * @author: Nitendra Verma
 * @version: June 8,2013
 */
import java.util.Scanner;
public class Magic
{
    int n,ntemp;  //instace variable to store the number
    public Magic()  //default constructor, assigns 0 to n
    {
        n=0;
    }
    
    public void getnum(int nn)  //metod, assigns the parameter value to the number
    {
        n=nn;
    }
    
    public int Sum_of_digits()  //method, returns the sum of digits of number 
    {
        int n1,r1,sum=0;
        ntemp=n;
        do      //outer loop
        {
        sum=0;  
        do     //inner loop
       {
           n1=n/10;
           r1=n%10;
           sum+=r1;
           n=n1;
        }
        while(n1!=0);
        n=sum;       
    }
    while(sum>=10);
    return sum;    //returning sum
    }
    
    public void ismagic()    //method, checks if the number is Magic Number 
    {
        int sum=Sum_of_digits();
        if(sum==1)
          System.out.println(ntemp+" is a Magic Number");
        else
          System.out.println(ntemp+" is not a Magic Number");
    }
    
    public static void main()
    {
        Magic ob=new Magic();   //creating object of Magic class
        Scanner in=new Scanner(System.in);  //creating object of Scanner class
        System.out.println("Enter a number");
        int num=in.nextInt();   //inputting number
        ob.getnum(num);         //calling method
        ob.ismagic();           //calling method
    }
}

/*---------------Program developed by: Nitendra Verma---------------*/
//For more details visit http://javawithnitendra.blogspot.in

Enter a number
172
172 is a Magic Number