c# - Find the maximum depth of a tree

Question

I have a tree data structure with N first-level child nodes that have childs too.

For example:

• Root
• Node1
• Node11
• Node111
• Node1111

Node12 Node2

• Node21
• Node211

I would like to know which of the braches has the biggest depth. As in the previous example it will be

Node1 - Node11 - Node111 - Node1111

that has a depth of four levels.

Any suggestion?

Thanks!

Answer 1

You must check all nodes. Several months ago I implemented this algorithm in this way:

class Node
{
    public String Name { get; private set; }
    public IList<Node> Childs { get; private set; }

    public Node(String name)
    {
        Name = name;
        Childs = new List<Node>();
    }

    public List<Node> Depth
    {
        get
        {
            List<Node> path = new List<Node>();
            foreach (Node node in Childs)
            {
                List<Node> tmp = node.Depth;
                if (tmp.Count > path.Count)
                    path = tmp;
            }
            path.Insert(0, this);
            return path;
        }
    }

    public override string ToString()
    {
        return Name;
    }
}

Example test:

Node node1111 = new Node("Node1111");
Node node111 = new Node("Node111");
Node node11 = new Node("Node11");
Node node12 = new Node("Node12");
Node node1 = new Node("Node1");
Node root = new Node("Root");
Node node2 = new Node("Node2");
Node node21 = new Node("Node21");
Node node211 = new Node("Node211");
root.Childs.Add(node1);
root.Childs.Add(node2);
node1.Childs.Add(node11);
node1.Childs.Add(node12);
node11.Childs.Add(node111);
node111.Childs.Add(node1111);
node2.Childs.Add(node21);
node21.Childs.Add(node211);

List<Node> path = root.Depth;
foreach (Node n in path)
    Console.Write(String.Format("{0} - ", n.ToString()));

Console.WriteLine();

Node node2111 = new Node("Node2111");
node2111.Childs.Add(new Node("Node21111"));
node211.Childs.Add(node2111);

path = root.Depth;
foreach (Node n in path)
    Console.Write(String.Format("{0} - ", n.ToString()));

Console.WriteLine();

Console output:

Root - Node1 - Node11 - Node111 - Node1111 -
Root - Node2 - Node21 - Node211 - Node2111 - Node21111 -