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.
递归DFS遍历两棵树，在相同的位置上，如果节点有一个为NULL或者两个节点的值不相同，则返回false，遍历完返回true.

class Solution {
public:
bool isSameTree(TreeNode *p, TreeNode *q) {
if(p==NULL&&q==NULL)return true;
else if(p==NULL||q==NULL||p->val!=q->val)return false;
else{
if(isSameTree(p->left,q->left)==false)return false;
return isSameTree(p->right,q->right);
}
}
};