[force buckle] the same tree

100. Same tree - Power button （LeetCode）

subject ：

Here are the root nodes of two binary trees  p  and  q , Write a function to check whether the two trees are the same .

If two trees are the same in structure , And the nodes have the same value , They are the same .

Ideas ：

Using recursive methods

If it's all empty return false

If one is empty and the other is not return false

If the values of two nodes are not equal ,return false

Judge whether the left subtree and the right subtree are the same

Code ：

bool isSameTree(struct TreeNode* p, struct TreeNode* q){
    if(p==NULL && q==NULL)
    {
        return true;
    }
    if(q&&!p)
    {
        return false;
    }
    if(p&&!q)
    {
        return false;
    }
    if(p->val != q->val)
    {
        return false;
    }
    bool ret1 = isSameTree(p->left,q->left);// Whether the left subtree is the same tree 
    bool ret2 = isSameTree(p->right,q->right);// Whether the right subtree is the same tree 
    return ret1 && ret2;
}