Class Solution


  • public class Solution
    extends Object
    623 - Add One Row to Tree.

    Medium

    Given the root of a binary tree and two integers val and depth, add a row of nodes with value val at the given depth depth.

    Note that the root node is at depth 1.

    The adding rule is:

    • Given the integer depth, for each not null tree node cur at the depth depth - 1, create two tree nodes with value val as cur’s left subtree root and right subtree root.
    • cur’s original left subtree should be the left subtree of the new left subtree root.
    • cur’s original right subtree should be the right subtree of the new right subtree root.
    • If depth == 1 that means there is no depth depth - 1 at all, then create a tree node with value val as the new root of the whole original tree, and the original tree is the new root’s left subtree.

    Example 1:

    Input: root = [4,2,6,3,1,5], val = 1, depth = 2

    Output: [4,1,1,2,null,null,6,3,1,5]

    Example 2:

    Input: root = [4,2,null,3,1], val = 1, depth = 3

    Output: [4,2,null,1,1,3,null,null,1]

    Constraints:

    • The number of nodes in the tree is in the range [1, 104].
    • The depth of the tree is in the range [1, 104].
    • -100 <= Node.val <= 100
    • -105 <= val <= 105
    • 1 <= depth <= the depth of tree + 1
    • Constructor Detail

      • Solution

        public Solution()
    • Method Detail

      • addOneRow

        public TreeNode addOneRow​(TreeNode root,
                                  int val,
                                  int depth)