Leetcode populating Next right pointers in each Node-----java

Given a binary tree

    struct Treelinknode {      treelinknode *left;      Treelinknode *right;      Treelinknode *next;    }

Populate each of the next pointer to the next right node. If There is no next right node, the next pointer should are set to NULL .

Initially, all next pointers is set to NULL .

Note:

• Constant extra space.
• You could assume that it was a perfect binary tree (ie, all leaves was at the same level, and every parent had both children).

For example,
Given the following perfect binary tree,

         1       /        2    3     /\  /     4  5  6  7

After calling your function, the tree is should look like:

         1, NULL       /        2, 3, null     /\  /     4->5->6->7, NULL

Change the structure of the tree.

The first use of the queue, not very soon.

/*** Definition for binary tree with next pointer. * public class Treelinknode {* Int. val; * Treelinknode left , right, next; * Treelinknode (int x) {val = x;} }*/ Public classSolution { Public voidConnect (Treelinknode root) {if(Root = =NULL)            return ; Queue Queue=NewLinkedlist<treelinknode>();        Queue.add (root);  while( !Queue.isempty ()) {treelinknode node=(Treelinknode) queue.poll (); if(Node.left! =NULL) {Node.left.next=Node.right; if(Node.next! =NULL) Node.right.next=Node.next.left;                Queue.add (Node.left);            Queue.add (Node.right); }        }            }}

The fastest is achieved without using the queue.

/*** Definition for binary tree with next pointer. * public class Treelinknode {* Int. val; * Treelinknode left, Right, Next; * Treelinknode (int x) {val = x;} }*/ Public classSolution { Public voidConnect (Treelinknode root) {if(Root = =NULL)            return ; Treelinknode Node1= Root,node2 =Root;  while(Node2.left! =NULL) {Node1=Node2.left;  while(Node2.next! =NULL) {Node2.left.next=Node2.right; Node2.right.next=Node2.next.left; Node2=Node2.next; } Node2.left.next=Node2.right; Node2=Node1; }            }}

Leetcode populating Next right pointers in each Node-----java