1class TreeNode {
2    constructor(val, left = null, right = null) {
3        this.val = val;
4        this.left = left;
5        this.right = right;
6    }
7}
8
9function createBinaryTree(descriptions) {
10    const nodeMap = new Map();
11    const children = new Set();
12
13    for (const [parent, child, isLeft] of descriptions) {
14        if (!nodeMap.has(parent)) {
15            nodeMap.set(parent, new TreeNode(parent));
16        }
17        if (!nodeMap.has(child)) {
18            nodeMap.set(child, new TreeNode(child));
19        }
20
21        if (isLeft === 1) {
22            nodeMap.get(parent).left = nodeMap.get(child);
23        } else {
24            nodeMap.get(parent).right = nodeMap.get(child);
25        }
26        children.add(child);
27    }
28
29    for (const [key, node] of nodeMap) {
30        if (!children.has(key)) {
31            return node;
32        }
33    }
34    return null;
35}
36