// Definition for a binary tree node.
struct TreeNode {
    int val;
    struct TreeNode *left;
    struct TreeNode *right;
};

//深度优先
bool isSameTree(struct TreeNode* p, struct TreeNode* q){
    if(p==NULL&&q==NULL)
        return true;
    if(p==NULL||q==NULL)
        return false;
    if(p->val==q->val)
        return isSameTree(p->left, q->left) && isSameTree(p->right, q->right);
    else
        return false;
}