Todo List class

gistfile1.java

public class Todo {
  private final Set<String> tasks = new HashSet<>();
  
  public void addItem(String task) {
    tasks.add(task);
  }
  
  public void deleteItem(String task) {
    tasks.remove(task);
  }
  
  public void viewList() {
    for (String str : tasks) {
      System.out.println(str);
    }
  }
  
  public static void main(String[] args) {
    Todo todo = new Todo();
    todo.addItem("Work on easy DP challenge");
    todo.addItem("Work on intermediate DP challenge");
    todo.viewList();
  }
}