Package g2101_2200.s2196_create_binary_tree_from_descriptions

Class Solution

java.lang.Object
g2101_2200.s2196_create_binary_tree_from_descriptions.Solution
public class Solution extends java.lang.Object
2196 - Create Binary Tree From Descriptions.

Medium

You are given a 2D integer array descriptions where descriptions[i] = [parenti, childi, isLefti] indicates that parenti is the parent of childi in a binary tree of unique values. Furthermore,

  • If isLefti == 1, then childi is the left child of parenti.
  • If isLefti == 0, then childi is the right child of parenti.

Construct the binary tree described by descriptions and return its root.

The test cases will be generated such that the binary tree is valid.

Example 1:

Input: descriptions = [[20,15,1],[20,17,0],[50,20,1],[50,80,0],[80,19,1]]

Output: [50,20,80,15,17,19]

Explanation: The root node is the node with value 50 since it has no parent.

The resulting binary tree is shown in the diagram.

Example 2:

Input: descriptions = [[1,2,1],[2,3,0],[3,4,1]]

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

Explanation: The root node is the node with value 1 since it has no parent.

The resulting binary tree is shown in the diagram.

Constraints:

  • 1 <= descriptions.length <= 104
  • descriptions[i].length == 3
  • 1 <= parenti, childi <= 105
  • 0 <= isLefti <= 1
  • The binary tree described by descriptions is valid.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    TreeNode
    createBinaryTree(int[][] descriptions)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • createBinaryTree

      public TreeNode createBinaryTree(int[][] descriptions)