LUCKY NUMBER

PROGRAM : LUCKY NUMBER

QUESTION:

Consider the sequence of natural numbers.
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25 ………………………………….

Removing every second number produces the sequences
1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23 ………………………….

Removing every third number produces the sequences
1, 3, 7, 9, 13, 15, 19, 21, 25 ………………………….

This process continues indefinitely by removing the fourth, fifth…and so on, till after a fixed number of steps, certain natural numbers remain indefinitely. These are known as Lucky Numbers.

Write a program to generate and print lucky numbers less than a given number N.

SAMPLE INPUT :  N = 10
OUTPUT :  The Lucky numbers less than 10 are:     1     3     7

SAMPLE INPUT :  N = 25
OUTPUT :  The Lucky numbers less than 25 are:     1     3     7     13     19

SYNTAX

import java.io.*;

class LuckyNumbers

{

public static void main(String args[])throws IOException

{

BufferedReader br=new BufferedReader(new InputStreamReader(System.in));

System.out.print("Enter the Number of Elements : ");

int n=Integer.parseInt(br.readLine());

int a[]=new int[n];

int c=n;

for(int i=0;i<n;i++)

{ 

a[i]=i+1;

}

int del=1;

System.out.println("Lucky Number Operation :");

while(del<n)

{

for(int i=del; i<n; i+=del)

{

for(int j=i; j<n-1; j++)

{

a[j]=a[j+1];

}

n--;

}

del++;

for(int i=0; i<n; i++)

{

System.out.print(a[i]+"   ");

}

System.out.println();

}

System.out.print("Hence, the Lucky Numbers Less than "+c+" are : ");

for(int i=0; i<n; i++)

{

System.out.print(a[i]+"   ");

}

}

}