c# coding OOPs

Code on using Char

using System;
using System.Text;

              public class TextInput {

                     protected string _value;

                     public virtual void Add(char c)

                     {

                           _value += c.ToString();

                     }

                     public virtual string GetValue()

                     {

                           return _value;

                     }

              }

              public class NumericInput : TextInput

              {

                     public override void Add(char n)

                     {

                           if(Char.IsNumber(n))

                                  _value += n.ToString();

                     }

              }

              public class UserInput

              {

                     public static void Main(string[] args)

                     {

                           TextInput input = new NumericInput();

                           input.Add('1');

                           input.Add('a');

                           input.Add('0');

                           Console.WriteLine(input.GetValue());

                           Console.ReadLine();

                     }

              }

RESULT: 10


Code 2 : IndexOf and Substring

using System;

public class Path
{
    public string CurrentPath { get; private set; }

    public Path(string path)
    {
        this.CurrentPath = path;
    }

    public void Cd(string newPath)
    {
        string[] folders = CurrentPath.Split('/');
        if(newPath.IndexOf("..")<0)
            CurrentPath += "/" + newPath;
        else
        {
            CurrentPath = CurrentPath.Substring(0, CurrentPath.LastIndexOf("/"));
       
            CurrentPath += newPath.Substring(2, newPath.Length -2);
        }
     
   
    }

    public static void Main(string[] args)
    {
        Path path = new Path("/a/b/c/d");
        path.Cd("../x");
        Console.WriteLine(path.CurrentPath);
    }
}

RESULTS : /a/b/c/x 

Unresolved - Binary Tree Search

using System;

public class Node

{

       public int Value { get; set; }

       public Node Left { get; set; }

       public Node Right { get; set; }

       public Node(int value, Node left, Node right)

       {

              Value = value;

              Left = left;

              Right = right;

       }

}

public class BinarySearchTree

{

       public static bool Contains(Node root, int value)

       {

              if (root == null) return false;

              if (root.Value == value)

                     return true;

              else if (root.Value < value)

                     return Contains(root.Right, value);

              else

                     return Contains(root.Left, value);

       }

       public static void Main(string[] args)

       {

              Node n1 = new Node(1, null, null);

              Node n3 = new Node(3, null, null);

              Node n2 = new Node(2, n1, n3);

              Console.WriteLine(Contains(n2, 3));

              Console.ReadLine();

       }

}

Palindrome Test

public class Palindrome
{
public static bool IsPalindrome(string word)
{

if (word.ToLower() == ReverseString(word.ToLower()))
return true;
return false;
}

public static void Main(string[] args)
{
Console.WriteLine(Palindrome.IsPalindrome("Deleveled"));
Console.ReadLine();
}

public static string ReverseString(string s)
{
char[] arr = s.ToCharArray();
Array.Reverse(arr);
return new string(arr);
}

}


-----------------------------

Another String Manipulation

-- imcomplete

using System;

public class Path

{

       public string CurrentPath { get; private set; }

       public Path(string path)

       {

              this.CurrentPath = path;

       }

       public void Cd(string newPath)

       {

              if (newPath == "/")  CurrentPath = "/";

              string[] cmd = newPath.Split('/');

             

              foreach (string cd in cmd)

                     switch (cd)

                     {

                           case "..":

                                  {

                                         CurrentPath = "/" + CurrentPath.Substring(1, CurrentPath.LastIndexOf('/') - 1);

                                         break;

                                  }

                           case "":

                                  {

                                         CurrentPath = ""; //to root this can only happen some cd(/x);

                                         break;

                                  }

                           default:

                                  {

                                         CurrentPath = CurrentPath + "/" + cd;

                                         break;

                                  }

                     }

       }

       public static void Main(string[] args)

       {

              Path path = new Path("/a/b/c/d");

              path.Cd("/x");

              Console.WriteLine(path.CurrentPath);

       Console.ReadLine();

       }

}

-------------
-- Smallest number left to be used ..
input = { 1, 3, 4, 5, 7 }; the answer = 2
input = { 1, 2, 3, 4, 7,9 }; the answer = 5

    class Program
    {
        static void Main(string[] args)
        {
   int[] input = { 1, 3, 4, 5, 7 };
   int result = solution(input);
   Console.WriteLine("small number to be used is {0}", result);
   Console.ReadLine();
        }

  public static int solution(int[] A)
  {
   int smallGuy = 1;
   // write your code in Java SE 8
   if (A.GetUpperBound(0) == 0) return smallGuy;
   if (A == null) return smallGuy;
   var aList = A.ToList();
 
   foreach (var number in A)
   {
    if (aList.IndexOf(smallGuy) >= 0)
     ++smallGuy;
   }
   return smallGuy;
  }
 }