Flatten Binary Tree to Linked List Total Accepted: 45093 Total Submissions: 156588

题目来自于LeetCode

https://leetcode.com/problems/flatten-binary-tree-to-linked-list/

Given a binary tree, flatten it to a linked list in-place.

For example,

Given

         1
        /        2   5
      / \        3   4   6

The flattened tree should look like:

   1
         2
             3
                 4
                     5
                         6

click to show hints.

Hide Tags

Tree Depth-first
Search

Have you met this question in a real interview?

/**
 * Definition for binary tree
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    void flatten(TreeNode *root) {
        if(root==NULL)
            return ;
         if(root->left!=NULL)
         {
             TreeNode *tmp=root->right;
             TreeNode *cur=root->left;
             root->right=root->left;
             while(cur->right!=NULL)
               cur=cur->right;
              cur->right=tmp;
              root->left=NULL;
         }
             flatten(root->right);
    }
};