package rebelsky.linear;

import java.util.Vector;

/**
 * An implementation of priority queues using Vectors in which the
 * elements are stored in no particular order, so the smallest
 * is identified during a call to get().
 * 
 * @author CSC152 2006S
 * @version 0.0000000001 of March 2006
 */
public class PQUV<T extends Comparable<T>> 
	implements PriorityQueue<T>
{

//	 +------------------+-------------------------------------
//	 | Design Decisions |
//	 +------------------+

/*
    We need a way to compare elements in the Vector.
    We will use the internal compareTo method.
    
 */
	
//	 +--------+-----------------------------------------------
//	 | Fields |
//	 +--------+

	Vector<T> values;
	
	
//	 +--------------+-----------------------------------------
//	 | Constructors |
//	 +--------------+

	public PQUV()
	{
		this.values = new Vector<T>();
	} // PQUV()
	
//	 +----------------+---------------------------------------
//	 | Public Methods |
//	 +----------------+
	
	public T get() {
		// Guess that the first element of the vector is the smallest
		// We'll keep track of position of smallest, rather than the value
		int alpha = 0;
		// Compare to each remaining element, updating the guess as appropriate
		for (int i = 1; i < this.values.size(); i++) {
			if (this.values.get(i).compareTo(this.values.get(alpha)) < 0) {
				alpha = i;
			} // if
		} // 
		// Remember the component
		T val = this.values.get(alpha);
		// Remove it (the following line is inefficient; we should
		// really take the last element and put it in space alpha).
		// Note: You may see this on an exam.
		this.values.remove(alpha);
		// We're done
		return val;
	} // get()

	public boolean isEmpty() {
		return this.values.isEmpty();
	} // isEmpty()

	public void put(T val) {
		// Put val in the first empty spot
		this.values.add(val);
	} // put(T)

} // class PQUV