Question

Java Programming

CS 209 Data Structure

1. Create a method that takes an ArrayList of String and returns a copy of that ArrayList with no duplicates.

The relative ordering of elements in the new ArrayList should be the same.

Sample Input: {"qwerty", "asdfgh", "qwer", "123", "qwerty", "123", "zxcvbn", "asdfgh"}

Sample Output: {"qwerty", "asdfgh", "qwer", "123", "zxcvbn"}

Answer 1

import java.util.*;
public class Main
{
   public static void main(String[] args) {
      
       // Get the ArrayList with duplicate values
ArrayList<String>
list = new ArrayList<>(
Arrays
.asList("qwerty", "asdfgh", "qwer", "123", "qwerty", "123", "zxcvbn", "asdfgh"));
  
// Print the Arraylist
System.out.println("ArrayList with duplicates: "
+ list);
  
// Remove duplicates
ArrayList<String>
newList = removeDuplicates(list);
  
// Print the ArrayList with duplicates removed
System.out.println("ArrayList with duplicates removed: "
+ newList);
}
  
  
   // Function to remove duplicates from an ArrayList
public static <T> ArrayList<T> removeDuplicates(ArrayList<T> list)
{
  
// Create a new ArrayList
ArrayList<T> newList = new ArrayList<T>();
  
// Traverse through the first list
for (T element : list) {
  
// If this element is not present in newList
// then add it
if (!newList.contains(element)) {
  
newList.add(element);
}
}
  
// return the new list
return newList;
}
  
}