LeetCode|Same Tree-java

题目：

Given two binary trees, write a function to check if they are equal or not.

Two binary trees are considered equal if they are structurally identical and the nodes have the same value.

思路：

判断两个二叉树是否相同，使用前序遍历，如果节点都为空或者两个节点的值相同则返回true，否则返回false

/** * Definition for a binary tree node. * 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;        }        if (p != null && q != null && p.val == q.val) {            return isSameTree(p.left, q.left) && isSameTree(p.right, q.right);        }        return false;    }}