LeetCode--100. 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.
代码：

/** * Definition for a binary tree node. * 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) || (p->val != q->val))            return false;        bool left = isSameTree(p->left, q->left);        bool right = isSameTree(p->right, q->right);        if(!left || !right)        {            return false;        }        return true;    }};