using System;

using System.Linq;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        //toddmoTime(); // 0.015s

        nosikTime(); // 0.016s

    }

    public static void toddmoTime(){

        foreach (var part in getParts("Category A|Category A > Sub Category 1|Category B|Category C|Category C > Sub Category 2"))

            Console.WriteLine(part);

        Console.WriteLine();

        Console.WriteLine("TEST 2");

        foreach (var part in getParts("Category A > THIS IS DATA IS REDUNDANT|Category A > Sub Category 1 > THIS IS DATA IS REDUNDANT|Category A > Sub Category 1 > Sub Sub Category 1|Category A > Sub Category 1 > Sub Sub Category 2"))

            Console.WriteLine(part);

    }

​

    public static List<string> getParts(string stringToParse)

    {

        var parts = stringToParse.Split('|').Select(part => part.Trim());

        return parts.Where(part => !parts.Any(comparePart => part != comparePart && comparePart.StartsWith(part))).ToList();

    }

    public static void nosikTime(){

        foreach (var part in Nosik("Category A|Category A > Sub Category 1|Category B|Category C|Category C > Sub Category 2"))

            Console.WriteLine(part);

        Console.WriteLine();

        Console.WriteLine("TEST 2");

        foreach (var part in Nosik("Category A > THIS IS DATA IS REDUNDANT|Category A > Sub Category 1 > THIS IS DATA IS REDUNDANT|Category A > Sub Category 1 > Sub Sub Category 1|Category A > Sub Category 1 > Sub Sub Category 2"))

            Console.WriteLine(part);

    }

​

    public static List<string> Nosik(string stringToParse)

    {

        List<string> firstSplitResults = stringToParse.Split('|').Select(p => p.Trim()).ToList();

        for (int i = 0; i < firstSplitResults.Count; i++)

        {

            int occCount = (stringToParse.Length - stringToParse.Replace(firstSplitResults[i], "").Length) / firstSplitResults[i].Length;

            if (occCount > 1)

            {

                firstSplitResults.RemoveAt(i);

                i--;

            }

        }

​

        return firstSplitResults;

    }

}