private static void heapify(int[] a) {
int startIndex = Heap.findParent(a.length - 1);
while (startIndex >= 0) {
siftDown(a, startIndex--, a.length);
}
}
private static void siftDown(int[] a, int k, int size) {
int maxIndex;
while (k >= 0 || k <= size - 1) {
maxIndex = Heap.findSwapNode(a, k, size, Heap.IS_MAX_HEAP);
if (maxIndex == k) return;
Helper.swap(a, k, maxIndex);
k = maxIndex;
}
}