static BinaryTreeNode buildBinaryTree(char[] preOrder, char[] inOrder, int start, int end) {
if (start > end) return null;
BinaryTreeNode rootNode = new BinaryTreeNode();
rootNode.setData(preOrder[preIndex]);
preIndex++;
// System.out.println(rootNode.getData());
if (start == end) return rootNode;
int dataIndex = search(inOrder, start, end, rootNode.getData());
if (dataIndex == -1) return null;
// System.out.println("Left Bounds: "+start+" "+(dataIndex-1));
rootNode.setLeft(buildBinaryTree(preOrder, inOrder, start, dataIndex - 1));
// System.out.println("Right Bounds: "+(dataIndex+1)+" "+end);
rootNode.setRight(buildBinaryTree(preOrder, inOrder, dataIndex + 1, end));
return rootNode;
}
public static void levelTravesal(BinaryTreeNode node) {
Queue queue = new LinkedList();
if (node == null) return;
queue.offer(node);
queue.offer(null);
int level = 0;
while (!queue.isEmpty()) {
BinaryTreeNode temp = (BinaryTreeNode) queue.poll();
if (temp == null) {
System.out.println("Level: " + level);
if (!queue.isEmpty()) queue.offer(null);
level++;
} else {
System.out.println(temp.data);
if (temp.getLeft() != null) queue.offer(temp.getLeft());
if (temp.getRight() != null) queue.offer(temp.getRight());
}
}
}