Solution.js

/**
 * Definition for a binary tree node.
 * function TreeNode(val, left, right) {
 *     this.val = (val===undefined ? 0 : val)
 *     this.left = (left===undefined ? null : left)
 *     this.right = (right===undefined ? null : right)
 * }
 */
/**
 * @param {TreeNode} root
 * @param {number} from
 * @param {number} to
 * @return {TreeNode}
 */
var correctBinaryTree = function (root) {
    const dfs = root => {
        if (!root || vis.has(root.right)) {
            return null;
        }
        vis.add(root);
        root.right = dfs(root.right);
        root.left = dfs(root.left);
        return root;
    };
    const vis = new Set();
    return dfs(root);
};