import java.util.*;


public class LinearScheduler {


   ArrayList contents; // ArrayList to keep tasks   

   public LinearScheduler() {
      contents = new ArrayList();
   }

   public void insert(Task t) {
      contents.add(t);
   }

   public boolean contains(Task t) {
      return contents.contains(t);
   }
      
   public Task next() {
      if (contents.isEmpty()) return null;

      int s = 0; // index of the Task with the smallest timestamp
      for (int i = 0; i < contents.size(); i++){
         if (((Task) contents.get(i)).stamp < ((Task) contents.get(s)).stamp) {
            s = i;
         }
      }
      Task smallest = (Task) contents.get(s);
      contents.remove(smallest);
      return smallest;   
   }

}