[Leetcode] Same Tree

/** * 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;        bool r=isSameTree(p->right, q->right);        bool l=isSameTree(p->left, q->left);        return r&&l;    }};