leetcode - Same Tree

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.

解题思路： DFS判断各个节点是否相同

/** * Definition for binary tree * struct TreeNode { *     int val; *     TreeNode *left; *     TreeNode *right; *     TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */class Solution {public:    bool isSameTree(TreeNode *p, TreeNode *q) {        if((p == NULL)&&(q == NULL))return true;        if((p == NULL)||(q == NULL))return false;        if(p->val != q->val)return false;        return isSameTree(p->left, q->left) && isSameTree(q->right, p->right);    }};