题目：Populating Next Right Pointers in Each Node

<span style="font-size:18px;">/*

 * LeetCode Populating Next Right Pointers in Each Node

 * 题目：为树的每一个节点添加一个next指针。指向树状结构排列时自己的右边节点，假设右边没有节点则置为null

 *  * Definition for binary tree with next pointer.

 * public class TreeLinkNode {

 *     int val;

 *     TreeLinkNode left, right, next;

 *     TreeLinkNode(int x) { val = x; }

 * }

 */

package javaTrain;

public class Train10 {

	public void connect(TreeLinkNode root) {

		if(root == null) return;

        root.next = null;

        connectHelp(root.left,root.right);

    }

	private void connectHelp(TreeLinkNode left,TreeLinkNode right){

		if(left == null && right == null) return;

		if(right == null) left.next = null;

		else left.next = right;

		connectHelp(left.left,left.right);

		connectHelp(left.right,right.left);

		connectHelp(right.left,right.right);

	}

}

</span>