recover-binary-search-tree

中序遍历，保存节点和节点值，重新赋值
https://www.cnblogs.com/grandyang/p/4298069.html
O(1）复杂度用Mirror遍历

class Solution {
public:
    void recoverTree(TreeNode *root) {
        vector<TreeNode*>list;
        vector<int>vals;
        inorder(root,list,vals);
        sort(vals.begin(),vals.end());
        for(int i=0;i<list.size();i++)
            list[i]->val=vals[i];
    }
    void inorder(TreeNode*root,vector<TreeNode*>&list,vector<int>&vals)
    {
        if(!root)return;
        inorder(root->left,list,vals);
        list.push_back(root),vals.push_back(root->val);
        inorder(root->right,list,vals);
    }
};