using System;
using System.Collections.Generic;
using System.Linq;

class Line
{
    public int id { get; set; }
    public string n1 { get; set; }
    public string n2 { get; set; }
    public string n3 { get; set; }
}

class Tools:IEqualityComparer<Line>
{
    private string MakeSort(ref Line x)
    {
        string tmp;
        if(x.n1.CompareTo(x.n2)<0)
        {
            tmp = x.n1;
            x.n1 = x.n2;
            x.n2 = tmp;
        }
        if (x.n2.CompareTo(x.n3) < 0)
        {
            tmp = x.n2;
            x.n2 = x.n3;
            x.n3 = tmp;
        }
        if (x.n1.CompareTo(x.n2) < 0)
        {
            tmp = x.n1;
            x.n1 = x.n2;
            x.n2 = tmp;
        }
        return x.n1 + x.n2 + x.n3;
    }


    #region IEqualityComparer<Line> 成员

    public bool Equals(Line x, Line y)
    {
        return MakeSort(ref x) == MakeSort(ref y);
    }

    public int GetHashCode(Line obj)
    {
        return MakeSort(ref obj).GetHashCode();
    }

    #endregion
}

class MyClass
{
    static void Main(string[] args)
    {
        //准备
        Line[] list = 
        {
            new Line{ id = 1, n1 = "c1", n2 = "c2", n3 = "c3" },
            new Line{ id = 2, n1 = "c2", n2 = "c3", n3 = "c1" },
            new Line{ id = 3, n1 = "c3", n2 = "c1", n3 = "c2" },
            new Line{ id = 4, n1 = "c4", n2 = "c1", n3 = "c5" },
        };

        //执行
        Line[] listOk = list.Distinct(new Tools()).ToArray();

        //验证
        foreach (var x in listOk)
        {
            Console.WriteLine(x.id + " " + x.n1 + " " + x.n2 + " " + x.n3);
        }
        //1 c3 c2 c1
        //4 c5 c4 c1

        Console.ReadKey();
    }
}