Im writing battleship valdiator on C# and want to use Regex to deal with it. Particulary, Im trying to check, that some characters are RIGHT OVER OTHER ones. So i`m using codeblock, that should do like that(i hope you will decode me): Regex.Matches(fieldS,
“000000([0-9]+at least one instance ofn){strlength-“000000”.Length}011110([0-9]+at least one instance ofn){strlength-“011110”.Length}000000″)

namespace Solution {
  using System;
  using System.Linq;
  using System.Text.RegularExpressions;
  using System.Collections;
  using System.Collections.Generic;
  
  public class BattleshipField {
    public static bool ValidateBattlefield(int[,] field) 
    {
      string fieldS = String.Join("",field.Cast<int>()
                                  .SelectMany((x,index)=>index==0?
                                               new String("000000000000n0"+x):
                                               index==field.Length-1?
                                               new String(x+"0n000000000000"):
                                               index%10==9?
                                              new String(x+"0"+"n"):
                                               index%10==0?
                                              new String("0"+x):
                                              new String(x+"")).ToList());
      
      if(Regex.Matches(fieldS,
                       "000000[0-9,n]{8}011110[0-9,n]{8}000000").Count()+
         Regex.Matches(fieldS,
                       "000n010[0-9,n]{11}010[0-9,n]{11}"+
                       "010[0-9,n]{11}010[0-9,n]{11}000").Count()
        !=1){
        Console.WriteLine(4+"n"+fieldS);
        return false;}// checking for battleship of length 4; 3,2,1 - analogically

      return true;
    }
  }
}

Ive searched for alike problems, but didnt find any answer. I want to get Regular Expression able to produce needed result.