Untitled

class Solution {
    public TreeNode createBinaryTree(int[][] descriptions) {
        Map<Integer, TreeNode> mp = new HashMap<>();
        Set<Integer> childSet = new HashSet<>();

        // Create nodes and set up parent-child relationships
        for (int[] description : descriptions) {
            int parent = description[0];
            int child = description[1];
            boolean isLeft = description[2] == 1;

            mp.putIfAbsent(parent, new TreeNode(parent));
            mp.putIfAbsent(child, new TreeNode(child));

            if (isLeft) {
                mp.get(parent).left = mp.get(child);
            } else {
                mp.get(parent).right = mp.get(child);
            }

            childSet.add(child);
        }

        // Find the root node (which is not any child)
        for (int[] description : descriptions) {
            int parent = description[0];
            if (!childSet.contains(parent)) {
                return mp.get(parent);
            }
        }

        return null;
    }