#416 · #2196 · Create Binary Tree From Descriptions(根据描述创建二叉树)

You are given a 2D array descriptions where descriptions[i] = [parent, child, isLeft] describes a binary tree edge. Return the root of the reconstructed tree. All node values are unique and the input describes a valid binary tree. Constraints: 1 <= descriptions.length <= 10^4, 1 <= parent, child <= 10^5.