Refactor: Replace Swap and Comparison Methods with SortUtils Utility Methods (TheAlgorithms#5246)

alxkm · Alex Klymenko · web-flow · commit 308bdcfc1927 · 2024-06-22T22:29:17.000+02:00
* Refactor: Replace Swap and Comparison Methods with SortUtils Utility Methods

* Rename parameter unsorted to array

---------

Co-authored-by: Alex Klymenko &lt;alx@alx.com&gt;
diff --git a/src/main/java/com/thealgorithms/sorts/HeapSort.java b/src/main/java/com/thealgorithms/sorts/HeapSort.java
@@ -9,48 +9,39 @@ public class HeapSort implements SortAlgorithm {
 
     /**
      * For simplicity, we are considering the heap root index as 1 instead of 0.
-     * It simplifies future calculations. Because of that we are decreasing the
-     * provided indexes by 1 in {@link #swap(Object[], int, int)} and
-     * {@link #less(Comparable[], int, int)} functions.
+     * This approach simplifies future calculations. As a result, we decrease
+     * the indexes by 1 when calling {@link SortUtils#less(Comparable, Comparable)}
+     * and provide adjusted values to the {@link SortUtils#swap(Object[], int, int)} methods.
      */
     @Override
-    public <T extends Comparable<T>> T[] sort(T[] unsorted) {
-        int n = unsorted.length;
-        heapify(unsorted, n);
+    public <T extends Comparable<T>> T[] sort(T[] array) {
+        int n = array.length;
+        heapify(array, n);
         while (n > 1) {
-            swap(unsorted, 1, n--);
-            siftDown(unsorted, 1, n);
+            SortUtils.swap(array, 0, n - 1);
+            n--;
+            siftDown(array, 1, n);
         }
-        return unsorted;
+        return array;
     }
 
-    private static <T extends Comparable<T>> void heapify(T[] unsorted, int n) {
+    private static <T extends Comparable<T>> void heapify(T[] array, int n) {
         for (int k = n / 2; k >= 1; k--) {
-            siftDown(unsorted, k, n);
+            siftDown(array, k, n);
         }
     }
 
-    private static <T extends Comparable<T>> void siftDown(T[] unsorted, int k, int n) {
+    private static <T extends Comparable<T>> void siftDown(T[] array, int k, int n) {
         while (2 * k <= n) {
             int j = 2 * k;
-            if (j < n && less(unsorted, j, j + 1)) {
+            if (j < n && SortUtils.less(array[j - 1], array[j])) {
                 j++;
             }
-            if (!less(unsorted, k, j)) {
+            if (!SortUtils.less(array[k - 1], array[j - 1])) {
                 break;
             }
-            swap(unsorted, k, j);
+            SortUtils.swap(array, k - 1, j - 1);
             k = j;
         }
     }
-
-    private static <T> void swap(T[] array, int idx, int idy) {
-        T swap = array[idx - 1];
-        array[idx - 1] = array[idy - 1];
-        array[idy - 1] = swap;
-    }
-
-    private static <T extends Comparable<T>> boolean less(T[] array, int idx, int idy) {
-        return array[idx - 1].compareTo(array[idy - 1]) < 0;
-    }
 }
