Работа с string[][]

using System;
using System.Text;
using System.Diagnostics;
string[][] listc;
        int selectc = 0;
 
public string[][] get_schemes()
        {
            string[][] lists = new string[20][];
            int listsi = 0;
            ProcessStartInfo procStartInfo = new ProcessStartInfo("cmd", "/c " + "powercfg -List");
            procStartInfo.RedirectStandardOutput = true;
            procStartInfo.UseShellExecute = false;
            procStartInfo.CreateNoWindow = true;
 
            Process proc = new Process();
            procStartInfo.StandardOutputEncoding = Encoding.GetEncoding(866);
            proc.StartInfo = procStartInfo;
            proc.Start();
 
            string[] list = proc.StandardOutput.ReadToEnd().Split('\n');
            for(int i=0;i< list.Length; i++)
            {
                int a = list[i].IndexOf(':') +1;
                if (a > 0)
                {
                    list[i] = list[i].Replace("  "," ");
                    string[] ion = list[i].Substring(a).Split(' ');
                    lists[listsi++] = ion;
                    if (ion.Length > 2) selectc = listsi;
                    if (listsi >= 20) break;
                }
                Array.Resize(ref lists, listsi);
            }
            return lists;
        }

 Array.Resize(ref lists, listsi);

using System;
using System.Runtime.InteropServices;
using System.Collections.Generic;
 
public class Program
{
    [DllImport("PowrProf.dll")]
    public static extern UInt32 PowerEnumerate(IntPtr RootPowerKey, IntPtr SchemeGuid, IntPtr SubGroupOfPowerSettingGuid, UInt32 AcessFlags, UInt32 Index, ref Guid Buffer, ref UInt32 BufferSize);
 
    [DllImport("PowrProf.dll")]
    public static extern UInt32 PowerReadFriendlyName(IntPtr RootPowerKey, ref Guid SchemeGuid, IntPtr SubGroupOfPowerSettingGuid, IntPtr PowerSettingGuid, IntPtr Buffer, ref UInt32 BufferSize);
 
    public enum AccessFlags : uint
    {
        ACCESS_SCHEME = 16,
        ACCESS_SUBGROUP = 17,
        ACCESS_INDIVIDUAL_SETTING = 18
    }
 
    private static string ReadFriendlyName(Guid schemeGuid)
    {
        uint sizeName = 1024;
        IntPtr pSizeName = Marshal.AllocHGlobal((int)sizeName);
 
        string friendlyName;
 
        try
        {
            PowerReadFriendlyName(IntPtr.Zero, ref schemeGuid, IntPtr.Zero, IntPtr.Zero, pSizeName, ref sizeName);
            friendlyName = Marshal.PtrToStringUni(pSizeName);
        }
        finally
        {
            Marshal.FreeHGlobal(pSizeName);
        }
 
        return friendlyName;
    }
 
    public static IEnumerable<Guid> GetAll()
    {
        var schemeGuid = Guid.Empty;
 
        uint sizeSchemeGuid = (uint)Marshal.SizeOf(typeof(Guid));
        uint schemeIndex = 0;
 
        while (PowerEnumerate(IntPtr.Zero, IntPtr.Zero, IntPtr.Zero, (uint)AccessFlags.ACCESS_SCHEME, schemeIndex, ref schemeGuid, ref sizeSchemeGuid) == 0)
        {
            yield return schemeGuid;
            schemeIndex++;
        }
    }
 
    public static void Main()
    {
        var guidPlans = GetAll();
 
        foreach (Guid guidPlan in guidPlans)
        {
            Console.WriteLine($"{guidPlan} {ReadFriendlyName(guidPlan)}");
        }
 
        Console.ReadKey();
    }
}