LeetCode 114. Flatten Binary Tree to Linked List

代码：

class Solution {public:    void flatten(TreeNode *root)     {        if (root == NULL)        {        return ;        }        flatten( root->left );flatten( root->right );                auto left_right_most = find_right_most(root->left);        if (left_right_most != NULL)        {        left_right_most->right = root->right;        root->right = root->left;        root->left = NULL;        }    }private:TreeNode *find_right_most(TreeNode* node){while (node!=NULL && node->right!=NULL){node = node->right;}return node;}};