static void Main(string[] args)
{
    OpenLock();
}

private static void OpenLock()
{
     string[] deadends = new string[] { "1234", "5678" };
     int count = OpenLock(deadends, "1235");
     Console.WriteLine($"最小步數: {count}");
     Console.ReadKey();
}

 /// <summary>
 /// 打開密碼鎖
 /// </summary>
 /// <param name="deadends">死亡密碼</param>
 /// <param name="target">目標密碼</param>
 /// <returns></returns>
 public static int OpenLock(string[] deadends, string target)
 {
     //使用 HashSet 避免有重覆死亡密碼
     var dead = new HashSet<string>(deadends);      
     var visited = new HashSet<string>();//訪問過清單
     var queue = new Queue<string>();
     
     //添加元素
     queue.Enqueue("0000");
     visited.Add("0000");

     int steps = 0;
     while (queue.Count > 0)
     {
         int size = queue.Count;
         for (int i = 0; i < size; i++)
         {
             var current = queue.Dequeue();
             if (dead.Contains(current)) continue;
             if (current == target) return steps;

             foreach (var next in GetNext(current))
             {                    
                 Console.WriteLine($"經過順序: {next}");
                 
                 /*  初始化: 0000 開始轉會如下
                     經過順序: 1000
                     經過順序: 9000
                     經過順序: 0100
                     經過順序: 0900
                     經過順序: 0010
                     經過順序: 0090
                     經過順序: 0001
                     經過順序: 0009 
                 */
                 if (!visited.Contains(next))
                 {
                     queue.Enqueue(next);
                     visited.Add(next);
                 }
             }
         }
         steps++;
     }
     return -1; // 如果無法達到目標
 }

/// <summary>
/// 轉盤 每次 +1 -1
/// </summary>
/// <param name="combination"></param>
 /// <returns></returns>
 private static IEnumerable<string> GetNext(string combination)
 {
     char[] chars = combination.ToCharArray();
     for (int i = 0; i < 4; i++)
     {
         char c = chars[i];
         chars[i] = c == '9' ? '0' : (char)(c + 1);
         yield return new System.String(chars);
         chars[i] = c == '0' ? '9' : (char)(c - 1);
         yield return new System.String(chars);
         chars[i] = c;
     }
 }