0. 题目

Given two binary trees, write a function to check if they are the same or not.
Two binary trees are considered the same if they are structurally identical and the nodes have the same value.

1. c++版本

思想1， 这个方法是用迭代的思想，只有有一点不相等，就直接返回 false

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

升级版本，其实就是中序遍历, 不过中序遍历忘记了……

 void preOrder(TreeNode* p, vector<int>& result) {
        if (p) {
            result.push_back(p->val);
            preOrder(p->left, result);
            preOrder(p->right, result);
        }
        result.push_back(INT_MIN);
    }
    bool isSameTree(TreeNode* p, TreeNode* q) {
        vector<int> result1, result2;
        preOrder(p,result1 );
        preOrder(q, result2);
        if (result1 == result2) 
            return true;
        return false;
    }

2. python版本

TODO