| English | 简体中文 |
2196. Create Binary Tree From Descriptions
You are given a 2D integer array
descriptions[i] = [parenti, childi, isLefti] indicates that
parenti is the parent of
childi in a binary tree of unique values. Furthermore,
isLefti == 1, then
childiis the left child of
isLefti == 0, then
childiis the right child of
Construct the binary tree described by
descriptions and return its root.
The test cases will be generated such that the binary tree is valid.
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.
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.
1 <= descriptions.length <= 104
descriptions[i].length == 3
1 <= parenti, childi <= 105
0 <= isLefti <= 1
- The binary tree described by