Leetcode-flatten Binary to Linked List__leetcode

Given a binary tree and 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

The general meaning of this question is to put the two-fork tree in the first order traversal sequence string. For example, the first sequence traversal sequence of the two-fork tree on the above graph is 1,2,3,4,5,6. And then chained up in a tree structure is the following binary tree.

    public void Flatten (TreeNode root) {
        if (root = null) return;

        TreeNode left = Root.left;
        TreeNode right = Root.right;

        Root.left = null;

        Flatten (left);
        Flatten (right);

        Root.right = left;
        TreeNode cur = root;
        while (cur.right!= null) cur = cur.right;
        Cur.right = right;
    

The code is straightforward, but it's not a good thought. Remember that the tree is due to its own recursive characteristics (as his definition is). So, it's very good to handle it in a recursive way.

The general processing mode of the sensory tree is:

handle left;
process right;
join Root

Of course, obviously the above is the subsequent traversal, so the tree's processing mode and the tree traversal pattern is basically consistent, the basic is to transform three depth traversal and a hierarchical traversal algorithm. Remember, remember, remember ...