Final answer:
The student is looking to implement a method within a BinaryTreeList class that constructs the path from the root to a specific node and throws an exception if the node is not found in the tree.
Step-by-step explanation:
The student is asking how to write a method in a binary tree class that returns the path from the root to a given node. If the node specified by the user does not exist in the tree, an IllegalArgumentException must be thrown. Typically, such a feature would be implemented in a class that represents a binary tree, where each node in the tree is connected and has at most two children.If the given node is not present in the tree, an IllegalArgumentException is thrown. This method can be called on an instance of the BinaryTreeList class to get the path from the root to a specific node.
To implement the pathFromRoot method, one would start from the root of the tree and traverse the tree until the target node is found. During traversal, references to the nodes along the path are added to a list. This list is then returned once the target node is reached. If the target node cannot be found, an exception is thrown, indicating an error. This traversal could be implemented either iteratively or recursively.