Remove Duplicates

// Java program to remove duplicate characters from a string
import java.util.*;

public class RemoveDuplicates {
    public static void main(String[] args) {
        String input = "programming";
        String result = removeDuplicates(input);
        System.out.println("Original: " + input);
        System.out.println("Without Duplicates: " + result);
    }

    public static String removeDuplicates(String str) {
        StringBuilder output = new StringBuilder();
        Set seen = new HashSet<>();

        for (char ch : str.toCharArray()) {
            if (!seen.contains(ch)) {
                seen.add(ch);
                output.append(ch);
            }
        }

        return output.toString();
    }
}