leetcode第一刷_Same Tree

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(p->right, q->right);
}
};