/* Homework 6
 * 
 * 
 */

/* A Foo object is a pair(BinaryHeap element, element's location), 
*  which is stored in the BInaryHeap hashtable with element value as the key
* This is needed because a 'bucket' in the hashtable can contain more than 
* one element in the linked list. The address of a 'bucket' is the hashcode 
* of an element value. Now, more than one element can have the same hashcode. 
* Hence, more than one element location can end up in one bucket. Now, to find 
* out which location belongs to which element, we need to store the location 
* along with the element in a pair to avoid any error. The hashcode() method
* calculates the hashcode of the element. The equals() method helps us to find 
* the right location for an element. Once a list is selected we compare the element
* with the element of the (element, location) pair. When a match is found, we
* return the location for that particular element. That is our answer.
*/

public class Foo {
	
	int location;  // location in binary heap array
	Object element;  // element from the heap
	
	// constructor to create a Foo without a location. 
	public Foo(Object x){
		element = x;
		location = -99;
	}
	
	// constructor sets the element and location with given values
	public Foo(Object x, int loc){
		element = x;
		location = loc;
	}
	
	// uses the hashCode of the element stored in the Foo as the hash code of a Foo object
	public int hashCode(){
		return element.hashCode();
	}
	
	// equals method used to compare two Foo objects - makes sure only the element value is compared,
	// and not the location or the (value, location) pair
	public boolean equals(Object o){
		if(o instanceof Foo){
			if (this.element.equals(((Foo)o).element)){
				return true;
			}
		}
		return false;
	}

}