using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
public class Tree : IEnumerable where TreeNode : IComparable {
public Tree(TreeNode nodeValue) {
this.NodeData = nodeValue;
this.LeftTree = null;
this.RightTree = null;
}
public void Insert(TreeNode newItem) {
TreeNode currentNodeValue = this.NodeData;
if (currentNodeValue.CompareTo(newItem) > 0) {
if (this.LeftTree == null) {
this.LeftTree = new Tree(newItem);
} else {
this.LeftTree.Insert(newItem);
}
} else {
if (this.RightTree == null) {
this.RightTree = new Tree(newItem);
} else {
this.RightTree.Insert(newItem);
}
}
}
public void WalkTree() {
if (this.LeftTree != null) {
this.LeftTree.WalkTree();
}
Console.WriteLine(this.NodeData.ToString());
if (this.RightTree != null) {
this.RightTree.WalkTree();
}
}
public TreeNode NodeData { get; set; }
public Tree LeftTree { get; set; }
public Tree RightTree { get; set; }
IEnumerator IEnumerable.GetEnumerator() {
if (this.LeftTree != null) {
foreach (TreeNode item in this.LeftTree) {
yield return item;
}
}
yield return this.NodeData;
if (this.RightTree != null) {
foreach (TreeNode item in this.RightTree) {
yield return item;
}
}
}
System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() {
throw new NotImplementedException();
}
}
class Employee : IComparable {
public string FirstName { get; set; }
public string LastName { get; set; }
public string Department { get; set; }
public int Id { get; set; }
public override string ToString() {
return String.Format("Id: {0}, Name: {1} {2}, Dept: {3}", this.Id, this.FirstName, this.LastName, this.Department);
}
int IComparable.CompareTo(Employee other) {
if (other == null)
return 1;
if (this.Id > other.Id)
return 1;
if (this.Id < other.Id)
return -1;
return 0;
}
}
class Program {
static void Main() {
Tree empTree = new Tree(new Employee { Id = 1, FirstName = "Janet", LastName = "Gates", Department = "IT" });
empTree.Insert(new Employee { Id = 2, FirstName = "O", LastName = "G", Department = "Marketing" });
empTree.Insert(new Employee { Id = 4, FirstName = "K", LastName = "H", Department = "IT" });
empTree.Insert(new Employee { Id = 6, FirstName = "L", LastName = "H", Department = "Sales" });
empTree.Insert(new Employee { Id = 3, FirstName = "E", LastName = "L", Department = "Sales" });
empTree.Insert(new Employee { Id = 5, FirstName = "D", LastName = "L", Department = "Marketing" });
var depts = empTree.Select(d => d.Department).Distinct();
foreach (var dept in depts)
Console.WriteLine("Department: {0}", dept);
}
}