ans this.

Active member

hi...

1.....please give me the java code tovfind primorialof a number...............

primorial of n is product of prime nos below or equal to n.

eg: primorial of is 2*3*5 which is 30

2.......write whether a nuimber is armstrong like.....

eg: 165033 is 16^3 + 50^3 + 33^3

Active member

1)

import java.io.*;
class prim
{
int prime=0,sum=1;
public void pp(int num)
{
for(int j=2;j<=num/2;j++)
{
if(num!=j)
{
if(num%j!=0)
{
prime=0;
}
else if(num%j==0)
{
prime=1;
}
}
}
}

public void ans(int n)
{
for(int i=2;i<=n;i++)
{
pp(i);
if(prime==0)
{
sum=sum*i;
System.out.println(i+" is Prime");
}
else
System.out.println(i+"is not prime");
}
System.out.println("Primorial of "+n+" is "+sum);
}
}

NOTE:

the first method pp() is to find whether a num is prime or not

the second method ans() is to find the prime nums till n and then find their product.

OUTPUT:

if n=5: output is:

2 is Prime
3 is Prime
4is not prime
5 is Prime
Primorial of 5 is 30

hope you understood

Active member

hey amstrong num is a number whose sum of the cubes of its digits is equal to the number itself.

Active member

arrey..no reply?

Active member

yes anu ur rite
dats armstrong
bt no need 2 wry if in icse dey give ny such question den they vry well explin wt it is

Active member

yeah apurva is rite...

Active member

so please give aprogram for armstrong nos

Active member

import java.io.*;
class armstrongno
{
public static void main() throws IOException
{
DataInputStream in = new DataInputStream (System.in);
System.out.println("enter no.");
int n =Integer.parseInt(in.readLine());
int i =n;
int sum=0;
int k;
while (i!=0)
{
k = i%10;
sum = sum+(k*k*k);
i = i/10;
}
if (sum==n)
System.out.println(n+" is an armstrong no.");
else
System.out.println(n+" is not an armstrong no.");
}}

Active member

pls check if it comes =)

Active member

as-24 it didnt works...its sayin 165033 not armstrong

Active member

mport java.io.*;
class armstrongno
{
public static void main() throws IOException
{
DataInputStream in = new DataInputStream (System.in);
System.out.println("enter no.");
int num =Integer.parseInt(in.readLine());int num1=num,sum=0,rem=0;while(num1>0){rem=num1%10;sum=sum+(int)(Math.pow(rem,3));num1=num1/10;}if(sum==num){System.out.println("armstrong");elseSystem.out.println(" Not Armstrong");}}

Active member

hey 165033=1^3 + 6^3 + 5^3 + 3^3 + 3^3
= 1+216+125+9+9
!= 360

so, 165033 is nt amstrong num hari.

Active member

my dear friend hari..
da code is absolutely crct..an armstrong number is one, da sum of da cubes of invidual digits of which is qual to the number itself Ex:153 1^3+5^3+3^3=1+125+27=158 bt 165033 is nt armstrong 1^3+6^3+5^3+0^3+3^3+3^3=1+216+125+0+27+27=360 hope u get it.. Smile

Active member

try no. 371, it'll come

Subject: Re: ans this. Thu Dec 31, 2009 1:29 pm

THANK YOU ALL cheers