Merge branch 'heapsort' into main

src/main/java/algorithmcomparison/Heapsort.java

+package algorithmcomparison;
+
+public class Heapsort {
+
+	// Class where data is sorted with heap sort
+	
+	public static int[] sort(int data[]) {
+		
+		int arr[] = data.clone();
+ 
+        // Build heap (rearrange array)
+        for (int i = arr.length / 2 - 1; i >= 0; i--)
+            heapify(arr, arr.length, i);
+ 
+        // One by one extract an element from heap
+        for (int i = arr.length - 1; i > 0; i--) {
+            // Move current root to end
+            int temp = arr[0];
+            arr[0] = arr[i];
+            arr[i] = temp;
+ 
+            // call max heapify on the reduced heap
+            heapify(arr, i, 0);
+        }
+        
+        return arr;
+    }
+	
+	public static void heapify(int arr[], int n, int i)
+    {
+        int biggest = i; // Initialize biggest as root
+        int left = 2 * i + 1; // left = 2*i + 1
+        int right = 2 * i + 2; // right = 2*i + 2
+ 
+        // If left child is larger than root
+        if (left < n && arr[left] > arr[biggest])
+            biggest = left;
+ 
+        // If right child is larger than largest so far
+        if (right < n && arr[right] > arr[biggest])
+            biggest = right;
+ 
+        // If largest is not root
+        if (biggest != i) {
+            int swap = arr[i];
+            arr[i] = arr[biggest];
+            arr[biggest] = swap;
+ 
+            // Recursively heapify the affected sub-tree
+            heapify(arr, n, biggest);
+        }
+    }
+
+}

src/test/java/algorithmcomparison/HeapsortTests.java

+package algorithmcomparison;
+
+import net.jqwik.api.*;
+
+import java.util.Arrays;
+
+
+public class HeapsortTests {
+	/**
+	 *Tests if heapsort sorts the dataset correctly 
+	 * 
+	 * @param arr  The given test array
+	 * 
+	 * @return True if sorts correctly, otherwise returns false
+	 */
+	@Property
+	boolean must_sort_correctly(@ForAll("array") Integer[]  arr) {
+		
+		int[] intArray = Arrays.stream(arr).mapToInt(Integer::intValue).toArray();
+		
+		int[] sorted = Heapsort.sort(intArray);
+		Arrays.sort(intArray);
+		return Arrays.equals(intArray, sorted);
+	}
+	
+	/**
+	 *Generates the test dataset
+	 *
+	 *@return The test dataset
+	 */
+	@Provide
+	Arbitrary<Integer[]> array() {
+		Arbitrary<Integer> integerArbitrary = Arbitraries.integers().between(1, 100);
+	    return integerArbitrary.array(Integer[].class).ofSize(100);
+	}
+}