题解 | #找到搜索二叉树中两个错误的节点#

 * struct TreeNode {
 *	int val;
 *	struct TreeNode *left;
 *	struct TreeNode *right;
 * };
 */

class Solution {
public:
    /**
     * 
     * @param root TreeNode类 the root
     * @return int整型vector
     */
    vector<int> res;
    void preorder(TreeNode* root,int &pre){//pre保存中序遍历前驱节点值
        if(!root)return;
        preorder(root->left,pre);
        if(root->val < pre){
            if(res.size() == 0){
                res.push_back(root->val);
                res.push_back(pre);
            }else res[0] = root->val;
        }
        pre = root->val;
        preorder(root->right,pre);
    }
    vector<int> findError(TreeNode* root) {
        // write code here
        int t = 0;
        preorder(root,t);
        return this->res;
    }
};