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.

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