Heap Element

A
package com.thealgorithms.datastructures.heaps;

/**
 * Class for heap elements.<br>
 *
 * <p>
 * A heap element contains two attributes: a key which will be used to build the
 * tree (int or double, either primitive type or object) and any kind of
 * IMMUTABLE object the user sees fit to carry any information he/she likes. Be
 * aware that the use of a mutable object might jeopardize the integrity of this
 * information.
 *
 * @author Nicolas Renard
 */
public class HeapElement {

    private final double key;
    private final Object additionalInfo;

    // Constructors
    /**
     * @param key : a number of primitive type 'double'
     * @param info : any kind of IMMUTABLE object. May be null, since the
     * purpose is only to carry additional information of use for the user
     */
    public HeapElement(double key, Object info) {
        this.key = key;
        this.additionalInfo = info;
    }

    /**
     * @param key : a number of primitive type 'int'
     * @param info : any kind of IMMUTABLE object. May be null, since the
     * purpose is only to carry additional information of use for the user
     */
    public HeapElement(int key, Object info) {
        this.key = key;
        this.additionalInfo = info;
    }

    /**
     * @param key : a number of object type 'Integer'
     * @param info : any kind of IMMUTABLE object. May be null, since the
     * purpose is only to carry additional information of use for the user
     */
    public HeapElement(Integer key, Object info) {
        this.key = key;
        this.additionalInfo = info;
    }

    /**
     * @param key : a number of object type 'Double'
     * @param info : any kind of IMMUTABLE object. May be null, since the
     * purpose is only to carry additional information of use for the user
     */
    public HeapElement(Double key, Object info) {
        this.key = key;
        this.additionalInfo = info;
    }

    /**
     * @param key : a number of primitive type 'double'
     */
    public HeapElement(double key) {
        this.key = key;
        this.additionalInfo = null;
    }

    /**
     * @param key : a number of primitive type 'int'
     */
    public HeapElement(int key) {
        this.key = key;
        this.additionalInfo = null;
    }

    /**
     * @param key : a number of object type 'Integer'
     */
    public HeapElement(Integer key) {
        this.key = key;
        this.additionalInfo = null;
    }

    /**
     * @param key : a number of object type 'Double'
     */
    public HeapElement(Double key) {
        this.key = key;
        this.additionalInfo = null;
    }

    // Getters
    /**
     * @return the object containing the additional info provided by the user.
     */
    public Object getInfo() {
        return additionalInfo;
    }

    /**
     * @return the key value of the element
     */
    public double getKey() {
        return key;
    }

    // Overridden object methods
    public String toString() {
        return "Key: " + key + " - " + additionalInfo.toString();
    }

    /**
     * @param otherHeapElement
     * @return true if the keys on both elements are identical and the
     * additional info objects are identical.
     */
    @Override
    public boolean equals(Object o) {
        if (o != null) {
            if (!(o instanceof HeapElement)) {
                return false;
            }
            HeapElement otherHeapElement = (HeapElement) o;
            return ((this.key == otherHeapElement.key) && (this.additionalInfo.equals(otherHeapElement.additionalInfo)));
        }
        return false;
    }

    @Override
    public int hashCode() {
        int result = 0;
        result = 31 * result + (int) key;
        result = 31 * result + (additionalInfo != null ? additionalInfo.hashCode() : 0);
        return result;
    }
}