2196. Create Binary Tree From Descriptions
Medium
30 Points
Array
Hash Table
Tree
Binary Tree
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,
Construct the binary tree described by descriptions and return its root.
The test cases will be generated such that the binary tree is valid.
Examples
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 <= 104descriptions[i].length == 31 <= parenti, childi <= 1050 <= isLefti <= 1The binary tree described by descriptions is valid.
2196. Create Binary Tree From Descriptions
Medium
30 Points
Array
Hash Table
Tree
Binary Tree
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,
Construct the binary tree described by descriptions and return its root.
The test cases will be generated such that the binary tree is valid.
Examples
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 <= 104descriptions[i].length == 31 <= parenti, childi <= 1050 <= isLefti <= 1The binary tree described by descriptions is valid.