BFS.cs

public static Tree<T> BFS<T>(Tree<T> root, int target) {
    // create Queue, and enqueue root node
    Queue<Tree<T>> queue = new Queue<Tree<T>>();
    queue.Enqueue(root);

    while (queue.Count > 0) {
        // dequeue first node
        Tree<T> node = queue.Dequeue();

        // compare target
        if (node.Value == target) {
            return node;
        }
        
        // enqueue all the children
        foreach (Tree<T> child in node.Children) {
            queue.Enqueue(child);
        }
    }
    
    return null;
}