100. Same Tree

Given two binary trees, write a function to check if they are the same or not.Two binary trees are considered the same if they are structurally identical and the nodes have the same value.Example 1:Input: 1 1 / \ / \ 2 3 2 3 [1,2,3], [1,2,3]Output: trueExample 2:Input: 1 1 / \ 2 2 [1,2], [1,null,2]Output: falseExample 3:Input: 1 1 / \ / \ 2 1 1 2 [1,2,1], [1,1,2]Output: false难度：easy题目：给定两二叉树，写函数检查它们是否相同。两个二叉树是否相同是由其结构和值都相同来决定。思路：递归/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */class Solution { public boolean isSameTree(TreeNode p, TreeNode q) { if (null == p && null != q || null != p && null == q) { return false; } if (null == p && null == q) { return true; } if (p.val != q.val) { return false; } return isSameTree(p.left, q.left) && isSameTree(p.right, q.right); }}