using System; using System.Linq; using System.Collections; using System.Collections.Generic; public class MyStringifiedNumberComparer : IEqualityComparer<string> { public bool Equals(string x, string y) { return (Int32.Parse(x) == Int32.Parse(y)); } public int GetHashCode(string obj) { return Int32.Parse(obj).ToString().GetHashCode(); } } public class MainClass { public static void Main() { string[] stringifiedNums = {"001", "49", "017", "0080", "00027", "2" }; bool contains = stringifiedNums.Contains("000271",new MyStringifiedNumberComparer()); Console.WriteLine(contains); } }