[leetcode]Same Tree - java 广度遍历

/**

 * Definition for binary tree

 * public class TreeNode {

 *     int val;

 *     TreeNode left;

 *     TreeNode right;

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

 * }

 */

public class Solution {

     public boolean isSameTree(TreeNode p, TreeNode q) {

        if(p==null && q==null){

            return true;

        }else if(p==null && q!=null){

            return false;

        }else if(p!=null && q==null){

            return false;

        }

        LinkedList<TreeNode> queue1 = new LinkedList<TreeNode>();

        queue1.add(p);

        LinkedList<TreeNode> queue2 = new LinkedList<TreeNode>();

        queue2.add(q);

        while (!queue1.isEmpty() && !queue2.isEmpty()){

            TreeNode node1 = queue1.remove();

            TreeNode node2 = queue2.remove();

            if(node1.val != node2.val){

                return false;

            }

            if(node1.left!=null){

                queue1.add(node1.left);

            }

            if(node2.left != null){

                queue2.add(node2.left);

            }

            if(queue1.size() != queue2.size()){

                return false;

            }

            if(node1.right!=null){

                queue1.add(node1.right);

            }

            if(node2.right!=null){

                queue2.add(node2.right);

            }

            if(queue1.size() !=  queue2.size()){

                return false;

            }

        }

        return true;

    }

}