Java for LeetCode 116 Populating Next Right Pointers in Each Node

Given a binary tree

    struct TreeLinkNode {
      TreeLinkNode *left;
      TreeLinkNode *right;
      TreeLinkNode *next;
    }

Populate each next pointer to point to its next right node. If there is no next right node, the next pointer should be set to NULL.

Initially, all next pointers are set to NULL.

解题思路：

直接观察即可写出递归代码，JAVA实现如下：

    public void connect(TreeLinkNode root) {
        if(root==null||root.left==null)
    		return;
    	root.left.next=root.right;
    	if(root.next!=null)
    		root.right.next=root.next.left;
    	connect(root.left);
    	connect(root.right);
    }