判断两个二叉树是否相等
bool isSameTree(struct TreeNode* p, struct TreeNode* q)
{//两个都为空if(p==NULL&&q==NULL){return true;}//有一个为空if(p==NULL||q==NULL){return false;}//两个不为空,但值不相同if(p->val!=q->val){return false;}//值相同return isSameTree(p->left,q->left)&& isSameTree(p->right,q->right);}