Remove Duplicates from a List of Words

Given a List of Strings, write a method removeDuplicates that removes duplicate words from the List and returns an ArrayList of all the unique words. The returned ArrayList should be lexically alphabetically.

Input: [Hi, Hello, Hey, Hi, Hello, Hey]

Output: [Hello, Hey, Hi]

Need a hand? Try out these hints, one at a time.

Quick hint to get things rolling

Think of this problem as a TreeSet 101. TreeSets not only hold only unique values but also maintain the natural order of the elements contained within. Since the output ArrayList needs to be lexically sorted, let us use a TreeSet to maintain the natural sorting order of inserted Strings.

A more detailed explanation

Move over the elements in a TreeSet to an ArrayList like so - ArrayList newList = new ArrayList(treeSet);

Final hint! You should be able to code the problem on viewing this.

1. Create an object of type TreeSet called treeSet.
2. Add all the Strings from the input list to treeSet.
3. Return new ArrayList(treeSet);.

public static ArrayList<String> removeDuplicates(List<String> input) {
    

}

This Coding Interview Question is available with an answer in the following programming languages :

Java

Python

Remove Duplicates from a List of Words

Quick hint to get things rolling

A more detailed explanation

Final hint! You should be able to code the problem on viewing this.

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This Coding Interview Question is available with an answer in the following programming languages :