CODE 16: Populating Next Right Pointers in Each Node II

Follow up for problem "Populating Next Right Pointers in Each Node".

What if the given tree could be any binary tree? Would your previous solution still work?

Note:

• You may only use constant extra space.

For example,
Given the following binary tree,

         1
       /  \
      2    3
     / \    \
    4   5    7

After calling your function, the tree should look like:

         1 -> NULL
       /  \
      2 -> 3 -> NULL
     / \    \
    4-> 5 -> 7 -> NULL

	public void connect(TreeLinkNode root) {
		// Start typing your Java solution below
		// DO NOT write main() function
		if (null == root) {
			return;
		}
		bfs(root);
	}

	private void bfs(TreeLinkNode root) {
		Queue<TreeLinkNode> queue = new LinkedList<TreeLinkNode>();
		queue.offer(root);
		int queueNumber = 1;
		int layerNumber = 0;
		TreeLinkNode tempNode = null;
		while (!queue.isEmpty()) {
			tempNode = queue.poll();
			queueNumber--;
			if (null != tempNode.left) {
				queue.offer(tempNode.left);
				layerNumber++;
			}
			if (null != tempNode.right) {
				queue.offer(tempNode.right);
				layerNumber++;
			}
			if (queueNumber != 0) {
				tempNode.next = queue.peek();
			} else {
				tempNode.next = null;
			}

			if (queueNumber == 0 && layerNumber != 0) {
				queueNumber = layerNumber;
				layerNumber = 0;
			}
		}
	}