Question

Create a static method with the appropriate inputs and outputs. Call each of them in the main method.

Write a method called isPermutaion() which takes in two List objects which contain the same types. It returns true if the Lists are permutations of each other and false if not. Two lists are permutations if they contain the same elements, including the same number of duplicates, but they don’t have to contain the elements in the same order. For example, [1,2, 4] and [2,1,4] are permutations of each other

Please Do this in Java.

Answer 1

//-------------- Permutation.java -----------

import java.util.*;

class Permutation
{
   //static method that prints the list and it's name.
   public static void printList(List<Integer> list,String listName)
   {
       System.out.println("\n------------- "+listName +" -----------------\n");
       System.out.println(list);
   }
   //function that returns a boolean value whether the two lists are permutation to each other
   public static boolean isPermutation(List<Integer> one,List<Integer> two)
   {
       //isPermutation checking without changing the contents of two lists passed.
       //copy elements of list one to tempOne list
      
       List<Integer> tempOne = new ArrayList<Integer>(one);
      
       //copy elements of list two to tempTwo list
       List<Integer> tempTwo = new ArrayList<Integer>(two);
       //Sort the two lists
       Collections.sort(tempOne);
       Collections.sort(tempTwo);
       //now compare the two lists.
       return tempOne.equals(tempTwo);
      
       //if you don't want to copy the contents of the two lists passed into temp lists
       //please put comments to all the above statements and uncomment below 3 statements
       //isPermutation checking by sorting the contents of two lists passed and comparing.
       //Collections.sort(one);
       //Collections.sort(two);
       //return one.equals(two);
      

   }
   //main method to test
   public static void main(String[] args)
   {
       //Test - 1
       //create two lists
       List<Integer> one = new ArrayList<Integer>();
       one.add(1);
       one.add(2);
       one.add(4);
      
       List<Integer> two = new ArrayList<Integer>();
       two.add(2);
       two.add(1);
       two.add(4);
      
       //print them
       printList(one,"List One");
       printList(two,"List Two");
       //call the isPermutation() method on the two lists.
       System.out.println("\nIs list One is Permutation of list Two: "+isPermutation(one,two));
      
   }
}
//
//if you have any doubts please comment and like the answer please.