Heapsort java

heapsort/Java/heapsort.java

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+public class ExampleHeapSort {
+    public static void main(String[] args) {
+        int[] numbers = { 14, 6, 9, 4, 56, 34, 21, 39 };
+        heapsort(numbers);
+        for (int h = 0; h < numbers.length; h++)
+            System.out.print(numbers[h]+ " ");
+    }
+
+    public static void heapsort(int[] a) {
+        for (int i = a.length / 2 - 1; i >= 0; i--)
+            shiftDown(a, i, a.length);
+        for (int i = a.length - 1; i > 0; i--) {
+            swap(a, 0, i);
+            shiftDown(a, 0, i);
+        }
+    }
+
+    private static void shiftDown(int[] a, int i, int n) {
+        int child;
+        int tmp;
+
+        for (tmp = a[i]; leftChild(i) < n; i = child) {
+            child = leftChild(i);
+            if (child != n - 1 && (a[child] < a[child + 1]))
+                child++;
+            if (tmp < a[child])
+                a[i] = a[child];
+            else
+                break;
+        }
+        a[i] = tmp;
+    }
+
+    private static int leftChild(int i) {
+        return 2 * i + 1;
+    }
+
+    public static void swap(int[] numbers, int i, int j) {
+        int temp = numbers[i];
+        numbers[i] = numbers[j];
+        numbers[j] = temp;
+    }
+}