private static BinarySearchTreeNode construct(int[] numArr, int start, int end) {
if (start > end) return null;
int middle = (start + end) / 2;
BinarySearchTreeNode node = new BinarySearchTreeNode(numArr[middle]);
node.setLeftNode(construct(numArr, start, middle - 1));
node.setRightNode(construct(numArr, middle + 1, end));
return node;
}
private static BinarySearchTreeNode trimTree(BinarySearchTreeNode node, int small, int large) {
if (node == null) return null;
node.setLeftNode(trimTree(node.getLeftNode(), small, large));
node.setRightNode(trimTree(node.getRightNode(), small, large));
if (node.getData() < small) return node.getRightNode();
else if (node.getData() > large) return node.getLeftNode();
else return node;
}