Question

A program in Bluej platform for generating permutations of a number?

Answer 1

import java.util.*;
public class Permutation
{
static Scanner sc=new Scanner(System.in);
public char[] arr;
public int count;

public Permutation(String word)
{
arr=word.toUpperCase().toCharArray(); count=0;
}
public void permute(int start)
{
if(start==arr.length-1) // TRIVIAL CASE
{
System.out.print(arr);System.out.print(" ");
if((getCount()+1)%5==0)System.out.println();
count++; return;
}
for(int i=start;i<arr.length;i++)
{ // SWAPPING i-th AND start-th ELEMENT
char temp=arr[i];
arr[i]=arr[start]; arr[start]=temp; permute(start+1);
// SWAPPING TO ORIGINAL POSITION
temp=arr[i]; arr[i]=arr[start]; arr[start]=temp;
}
}
public int getCount(){ return count; }
public static void main(String args[])
{
System.out.print("Enter The Word : ");
String word=sc.next(); System.out.println();
Permutation obj=new Permutation(word);
obj.permute(0); // BEGIN WITH 1ST CHAR
System.out.println("\nTotal No Of Permutation : "+obj.getCount());
}
}