/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
void flatten(TreeNode* root) {
TreeNode* now = root;
while (now)
{
if (now->left)
{
TreeNode* pre = now->left;
while (pre->right)
{
pre = pre->right;
}
pre->right = now->right;
now->right = now->left;
now->left = NULL;
}
now = now->right;
}
}
};