/*Clay Warlick

 Write a function f(a, b) which takes two character string 

 arguments and returns a string containing only the characters 

 found in both strings.

 -LINQ Intersect appears to be best solution 

*/

​

using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

    string text1 = "34567abb";

    string text2 = "3abcb";

    Console.WriteLine(compareChars(text1,text2));   

    }     

 // output = 3ab 

public static string compareChars(string x, string y)

{

    return new string(x.Intersect(y).ToArray());

}

}

​