using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var list1 = new List<Schema>();

        var list2 = new List<Schema>();

        var list3 = new List<Schema>();

        var list4 = new List<Schema>();

​

        list1.Add(new Schema() { High = 10, Low = 8, OpenValue = 7, Price = 8.5, Time = DateTime.Today.AddDays(-7), Volume = 234234232 });

        list2.Add(new Schema() { High = 10, Low = 8, OpenValue = 7, Price = 8.5, Time = DateTime.Today.AddDays(-6), Volume = 234234232 });

        list3.Add(new Schema() { High = 10, Low = 8, OpenValue = 7, Price = 8.5, Time = DateTime.Today.AddDays(-7), Volume = 234234232 });

        list4.Add(new Schema() { High = 10, Low = 8, OpenValue = 7, Price = 8.5, Time = DateTime.Today.AddDays(-7), Volume = 234234232 });

​

        var list = new List<List<Schema>> { list1, list2, list3, list4 };

​

        var final = list.MatchList();

​

        final.ForEach(d => Console.WriteLine(string.Format("{0}:{1}", final.IndexOf(d), d)));

    }

}

​

public class Schema

{

    public int High { get; set; }

    public int Low { get; set; }

    public int OpenValue { get; set; }

    public double Price { get; set; }

    public DateTime Time { get; set; }

    public int Volume { get; set; }

    public override bool Equals(object obj)

    {

        if (ReferenceEquals(null, obj)) return false;

        if (ReferenceEquals(this, obj)) return true;

        if (obj.GetType() != this.GetType()) return false;

        return Equals((Schema)obj);

    }

    protected bool Equals(Schema other)

    {

        return High == other.High && Low == other.Low && OpenValue == other.OpenValue && Price.Equals(other.Price) && Time.Equals(other.Time) && Volume == other.Volume;

    }

    public override int GetHashCode()

    {

        unchecked

        {

            int hashCode = High;

            hashCode = (hashCode * 397) ^ Low;

            hashCode = (hashCode * 397) ^ OpenValue;

            hashCode = (hashCode * 397) ^ Price.GetHashCode();

            hashCode = (hashCode * 397) ^ Time.GetHashCode();

            hashCode = (hashCode * 397) ^ Volume;

            return hashCode;

        }

    }

}

​

public static class ListExtension

{

    public static List<List<T>> MatchList<T>(this List<List<T>> list) where T : class

    {

        //will contain matched list element index

        var matchedList = new List<Tuple<int, int>>();

        for (var i = 0; i < list.Count - 1; i++)

        {

            for (var j = i + 1; j < list.Count; j++)

            {

                //add element to matchedList if all are equal.

                var iElement = list.ElementAt(i);

                var jElement = list.ElementAt(j);

                if (iElement.Count != jElement.Count) continue;

                var flag = !iElement.Where((t, k) => !iElement.ElementAt(k).Equals(jElement.ElementAt(k))).Any();

                if (flag)

                {

                    //add element here.

                    matchedList.Add(new Tuple<int, int>(i, j));

                }

            }

        }

​

        var item1 = matchedList.Select(d => d.Item1).ToList();

        var item2 = matchedList.Select(d => d.Item2).ToList();

        //distinct elements that matchced perfectly.

        var sameGroup = item1.Union(item2);

        for (var i = 0; i < list.Count; i++)

        {

            if (!sameGroup.Contains(i))

            {

                //make it null where it did not matched as your requirement

                list[i] = null;

            }

        }

        //finally return the updated list.

        return list;

    }

}