TreeExample.swift

class Node<T: Equatable> {
    var value: T
    weak var parent: Node<T>?
    var children: [Node<T>] = []
    
    init(value: T) {
        self.value = value
    }
    
    func add(child: Node<T>) {
        children.append(child)
        child.parent = self
    }
    
    func search(value: T) -> Node? {
        if value == self.value {
            return self
        }
        for child in children {
            if let valueFound = child.search(value: value) {
                return valueFound
            }
        }
        return nil
    }
}


class Tree<T: Equatable> {
    
    var root: Node<T>
    
    init(root: Node<T>) {
        self.root = root
    }
}