- * 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. + * A heap element contains two attributes: a key used for ordering in the heap + * (which can be of type int or double, either as primitive types or as wrapper objects) + * and an additional immutable object that can store any supplementary information the user desires. + * Note that using mutable objects may compromise the integrity of this information. + *
+ * + *+ * The key attribute is used to determine the order of elements in the heap, + * while the additionalInfo attribute can carry user-defined data associated with the key. + *
+ * + *+ * This class provides multiple constructors to accommodate various key types and includes + * methods to retrieve the key and additional information. + *
* * @author Nicolas Renard */ @@ -19,9 +29,10 @@ public class HeapElement { // 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 + * Creates a HeapElement with the specified key and additional information. + * + * @param key the key of the element (primitive type double) + * @param info any immutable object containing additional information, may be null */ public HeapElement(double key, Object info) { this.key = key; @@ -29,9 +40,10 @@ public class HeapElement { } /** - * @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 + * Creates a HeapElement with the specified key and additional information. + * + * @param key the key of the element (primitive type int) + * @param info any immutable object containing additional information, may be null */ public HeapElement(int key, Object info) { this.key = key; @@ -39,9 +51,10 @@ public class HeapElement { } /** - * @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 + * Creates a HeapElement with the specified key and additional information. + * + * @param key the key of the element (object type Integer) + * @param info any immutable object containing additional information, may be null */ public HeapElement(Integer key, Object info) { this.key = key; @@ -49,9 +62,10 @@ public class HeapElement { } /** - * @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 + * Creates a HeapElement with the specified key and additional information. + * + * @param key the key of the element (object type Double) + * @param info any immutable object containing additional information, may be null */ public HeapElement(Double key, Object info) { this.key = key; @@ -59,7 +73,9 @@ public class HeapElement { } /** - * @param key : a number of primitive type 'double' + * Creates a HeapElement with the specified key. + * + * @param key the key of the element (primitive type double) */ public HeapElement(double key) { this.key = key; @@ -67,7 +83,9 @@ public class HeapElement { } /** - * @param key : a number of primitive type 'int' + * Creates a HeapElement with the specified key. + * + * @param key the key of the element (primitive type int) */ public HeapElement(int key) { this.key = key; @@ -75,7 +93,9 @@ public class HeapElement { } /** - * @param key : a number of object type 'Integer' + * Creates a HeapElement with the specified key. + * + * @param key the key of the element (object type Integer) */ public HeapElement(Integer key) { this.key = key; @@ -83,7 +103,9 @@ public class HeapElement { } /** - * @param key : a number of object type 'Double' + * Creates a HeapElement with the specified key. + * + * @param key the key of the element (object type Double) */ public HeapElement(Double key) { this.key = key; @@ -92,46 +114,57 @@ public class HeapElement { // Getters /** - * @return the object containing the additional info provided by the user. + * Returns the object containing the additional information provided by the user. + * + * @return the additional information */ public Object getInfo() { return additionalInfo; } /** - * @return the key value of the element + * Returns the key value of the element. + * + * @return the key of the element */ public double getKey() { return key; } // Overridden object methods + /** + * Returns a string representation of the heap element. + * + * @return a string describing the key and additional information + */ + @Override public String toString() { - return "Key: " + key + " - " + additionalInfo.toString(); + return "Key: " + key + " - " + (additionalInfo != null ? additionalInfo.toString() : "No additional info"); } /** - * @param otherHeapElement - * @return true if the keys on both elements are identical and the - * additional info objects are identical. + * Compares this heap element to another object for equality. + * + * @param o the object to compare with + * @return true if the keys and additional information are identical, false otherwise */ @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))); + if (o instanceof HeapElement otherHeapElement) { + return this.key == otherHeapElement.key && (this.additionalInfo != null ? this.additionalInfo.equals(otherHeapElement.additionalInfo) : otherHeapElement.additionalInfo == null); } return false; } + /** + * Returns a hash code value for the heap element. + * + * @return a hash code value for this heap element + */ @Override public int hashCode() { - int result = 0; - result = 31 * result + (int) key; - result = 31 * result + (additionalInfo != null ? additionalInfo.hashCode() : 0); + int result = 31 * (int) key; + result += (additionalInfo != null) ? additionalInfo.hashCode() : 0; return result; } } diff --git a/src/test/java/com/thealgorithms/datastructures/heaps/HeapElementTest.java b/src/test/java/com/thealgorithms/datastructures/heaps/HeapElementTest.java new file mode 100644 index 000000000..d04a9de8a --- /dev/null +++ b/src/test/java/com/thealgorithms/datastructures/heaps/HeapElementTest.java @@ -0,0 +1,55 @@ +package com.thealgorithms.datastructures.heaps; + +import static org.junit.jupiter.api.Assertions.assertEquals; +import static org.junit.jupiter.api.Assertions.assertNotEquals; +import static org.junit.jupiter.api.Assertions.assertNull; + +import org.junit.jupiter.api.Test; + +class HeapElementTest { + + @Test + void testConstructorAndGetters() { + HeapElement element = new HeapElement(5.0, "Info"); + assertEquals(5.0, element.getKey()); + assertEquals("Info", element.getInfo()); + } + + @Test + void testConstructorWithNullInfo() { + HeapElement element = new HeapElement(10); + assertEquals(10, element.getKey()); + assertNull(element.getInfo()); + } + + @Test + void testToString() { + HeapElement element = new HeapElement(7.5, "TestInfo"); + assertEquals("Key: 7.5 - TestInfo", element.toString()); + + HeapElement elementWithoutInfo = new HeapElement(3); + assertEquals("Key: 3.0 - No additional info", elementWithoutInfo.toString()); + } + + @Test + void testEquals() { + HeapElement element1 = new HeapElement(2.5, "Data"); + HeapElement element2 = new HeapElement(2.5, "Data"); + HeapElement element3 = new HeapElement(3.0, "DifferentData"); + + assertEquals(element1, element2); // Same key and info + assertNotEquals(element1, element3); // Different key + assertNotEquals(null, element1); // Check for null + assertNotEquals("String", element1); // Check for different type + } + + @Test + void testHashCode() { + HeapElement element1 = new HeapElement(4, "HashMe"); + HeapElement element2 = new HeapElement(4, "HashMe"); + HeapElement element3 = new HeapElement(4, "DifferentHash"); + + assertEquals(element1.hashCode(), element2.hashCode()); // Same key and info + assertNotEquals(element1.hashCode(), element3.hashCode()); // Different info + } +}