using System;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine(isSpliceJoin("abaca", 2, "abaac"));

    }

​

    private static bool isSpliceJoin(String text, int len, String target)

    {

        List<string> substring = getSubstring(text, len);

        return permute(substring, 0, substring.Count - 1, target);

    }

​

    private static List<string> getSubstring(string text, int len)

    {

        List<string> ret = new List<string>();

        int subCounter = 0;

        int loopIndex = 0;

        int textLen = text.Length;

        do

        {

            subCounter = (textLen - loopIndex) > len ? len : textLen - loopIndex;

            ret.Add(text.Substring(loopIndex, subCounter));

            loopIndex += subCounter;

        }

        while (loopIndex != textLen);

        return ret;

    }

​

    private static bool permute(List<string> str, int start, int end, String target)

    {

        if (start == end)

        {

            return (string.Join("", str.ToArray()) == target);

        }

        else

        {

            for (int i = start; i <= end; i++)

            {

                str = swap(str, start, i);

                bool ret = permute(str, start + 1, end, target);

                str = swap(str, start, i);

                if (ret)

                    return true;

            }

        }

​

        return false;

    }

​

    public static List<string> swap(List<string> a, int i, int j)

    {

        string temp = a[i];

        a[i] = a[j];

        a[j] = temp;

        return a;

    }

}