DijkstraMethod/GraphIoUtilities.cs

using System;
using System.Collections.Generic;
using System.Linq;

// Класс для ввода/вывода графа
static class GraphIoUtilities
{
    static private readonly int MAX_AMOUNT = 20;

    static public Dictionary<char, int> GenerateCharToVertexId()
    {
        Dictionary<char, int> result = new Dictionary<char, int>();


        char letter = 'А';
        for (int i = 1; i <= MAX_AMOUNT; i++)
        {
            result[letter] = i;
            letter++;
        }

        return result;
    }

    static public Dictionary<int, char> GenerateVertexIdToChar()
    {
        Dictionary<int, char> result = new Dictionary<int, char>();


        char letter = 'А';
        for (int i = 1; i <= MAX_AMOUNT; i++)
        {
            result[i] = letter;
            letter++;
        }

        return result;
    }
}