public static int[] heapsort(int[] a) {
Maxheap heap = new Maxheap(a.length);
heap.arr = a;
heap.heapsize = a.length;
heap = heapify(heap);
while (heap.heapsize >= 1) {
int temp = heap.arr[0];
heap.arr[0] = heap.arr[heap.heapsize - 1];
heap.arr[heap.heapsize - 1] = temp;
heap.heapsize--;
heap.maxheapify(0);
}
a = heap.arr;
return a;
}
public static Maxheap heapify(Maxheap heap) {
int length = heap.heapsize;
for (int i = (length - 2) / 2; i >= 0; i--) {
heap.maxheapify(i);
}
return heap;
}