Package g2101_2200.s2196_create_binary_tree_from_descriptions

Class Solution

  • All Implemented Interfaces:
    
public final class Solution

    2196 - Create Binary Tree From Descriptions.

    Medium

    You are given a 2D integer array descriptions where <code>descriptionsi = parent<sub>i</sub>, child<sub>i</sub>, isLeft<sub>i</sub></code> indicates that <code>parent<sub>i</sub></code> is the parent of <code>child<sub>i</sub></code> in a binary tree of unique values. Furthermore,

    • If <code>isLeft<sub>i</sub> == 1</code>, then <code>child<sub>i</sub></code> is the left child of <code>parent<sub>i</sub></code>.

    • If <code>isLeft<sub>i</sub> == 0</code>, then <code>child<sub>i</sub></code> is the right child of <code>parent<sub>i</sub></code>.

    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:

    • <code>1 <= descriptions.length <= 10<sup>4</sup></code>

    • descriptions[i].length == 3

    • <code>1 <= parent<sub>i</sub>, child<sub>i</sub><= 10<sup>5</sup></code>

    • <code>0 <= isLeft<sub>i</sub><= 1</code>

    • The binary tree described by descriptions is valid.

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Field Summary

      Fields 
      Modifier and Type Field Description

    • Constructor Summary

      Constructors 
      Constructor Description
      Solution()

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final TreeNode createBinaryTree(Array<IntArray> descriptions)

      • Methods inherited from class java.lang.Object

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