Exemplo n.º 1
0
        private static bool GenerateString(LinkedList <int> soFar, HashSet <int> codes)
        {
            Console.WriteLine(soFar.Count);

            if (soFar.Count == (3 + Math.Pow(NumDigitsInCode, 4)))
            {
                return(true);
            }

            if (soFar.Count < 3)
            {
                for (int i = 0; i < LockStringGenerator.NumDigitsInCode; i++)
                {
                    soFar.AddLast(i);

                    if (LockStringGenerator.GenerateString(soFar, codes))
                    {
                        return(true);
                    }

                    soFar.RemoveLast();
                }

                return(false);
            }

            // We need to try tacking on all digits that give us new codes.
            for (int i = 0; i < LockStringGenerator.NumDigitsInCode; i++)
            {
                int newCode = GetNewCode(soFar, i);
                if (!codes.Contains(newCode))
                {
                    codes.Add(newCode);
                    soFar.AddLast(i);
                    if (LockStringGenerator.GenerateString(soFar, codes))
                    {
                        return(true);
                    }
                    soFar.RemoveLast();
                    codes.Remove(newCode);
                }
            }

            return(false);
        }
Exemplo n.º 2
0
        // Try by generating all permutations. There are 10,000 unique codes.
        // The optimal string is of length 10,003 because the first code is of
        // length 4 and then each additional appended digit generates a new unique code,
        // so 4 + 9,999 = 10,003.
        public static string GenerateString()
        {
            LinkedList <int> result = new LinkedList <int>();

            if (LockStringGenerator.GenerateString(result, new HashSet <int>()))
            {
                StringBuilder rval = new StringBuilder();
                foreach (int i in result)
                {
                    rval.Append(i);
                }
                return(rval.ToString());
            }
            else
            {
                return(null);
            }
        }