Adv2015/D07.1/Program.cs

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

namespace D07._1
{
    public class Program
    {
        public interface In { }

        public class Wire : In
        {
            public string Name;
        }

        public class Signal : In
        {
            public ushort Value;
        }

        public class Gate
        {
            public In L1;
            public In L2;
            public Wire R;

            public string Op;
        }

        public static Signal TestCircuit(List<Gate> gates, Gate gate)
        {
            if (gate.Op is null && gate.L1 is Signal s)
                return s;

            if (gate.L1 is Wire w1)
            {
                var l1g = gates.Where(g => g.R.Name == w1.Name).First();
                gate.L1 = TestCircuit(gates, l1g);
            }

            if (gate.L2 is Wire w2)
            {
                var l2g = gates.Where(g => g.R.Name == w2.Name).First();
                gate.L2 = TestCircuit(gates, l2g);
            }

            if (gate.R.Name == "a") return gate.L1 as Signal;
            if (gate.R.Name == "b") return new Signal() { Value = 956 };

            var result = operators[gate.Op]((gate.L1 as Signal)?.Value, (gate.L2 as Signal).Value);
            return new Signal() { Value = result };
        }

        static Dictionary<string, Func<ushort?, ushort, ushort>> operators = new Dictionary<string, Func<ushort?, ushort, ushort>>
            {
                { "AND", (a, b) => (ushort)(a & b) },
                { "OR", (a, b) => (ushort)(a | b) },
                { "NOT", (a, b) => (ushort)(~ b) },
                { "LSHIFT", (a, b) => (ushort)(a << b) },
                { "RSHIFT", (a, b) => (ushort)(a >> b) }
            };

        static void Main(string[] args)
        {
            if (args.Length < 1) throw new ArgumentException();
            if (File.Exists(args[0]) == false) throw new FileNotFoundException();

            Signal answer = TestSignalP1(args[0]);

            Console.WriteLine($"The answer is : {answer.Value}");
        }

        public static Signal TestSignalP1(string file)
        {
            List<Gate> gates = new List<Gate>();

            ParseFile(file, gates);

            var last = gates.Where(g => g.R.Name == "a").First();

            var answer = TestCircuit(gates, last);
            return answer;
        }

        public static void ParseFile(string f, List<Gate> gates)
        {
            using (var file = File.OpenText(f))
            {
                while (true)
                {
                    var line = file.ReadLine();
                    if (line == null) break;

                    ParseLine(gates, line);
                }
            }
        }

        private static void ParseLine(List<Gate> gates, string line)
        {
            var sp = line.Split(" -> ");
            string lpart = sp[0], rpart = sp[1];

            bool hasOp = false;

            In L1 = null, L2 = null;
            var gate = new Gate();

            SearchOperator(operators, line, lpart, ref hasOp, ref L1, ref L2, gate);

            if (hasOp == false)
            {
                if (ushort.TryParse(lpart, out ushort lv))
                {
                    L1 = new Signal() { Value = lv };
                }
                else
                {
                    L1 = new Wire() { Name = lpart };
                }
                gate.L1 = L1;
            }

            var R = new Wire() { Name = rpart };

            gate.R = R;

            gates.Add(gate);
        }

        private static void SearchOperator(Dictionary<string, Func<ushort?, ushort, ushort>> operators, string line, string lpart, ref bool hasOp, ref In L1, ref In L2, Gate gate)
        {
            foreach (var op in operators)
            {
                if (line.Contains(op.Key) == false) continue;

                hasOp = true;

                var lop = lpart.Split(op.Key);
                var a = lop[0].Trim(' ');
                var b = lop[1].Trim(' ');

                if (ushort.TryParse(a, out ushort aa))
                {
                    L1 = new Signal() { Value = aa };
                }
                else if (a != string.Empty)
                {
                    L1 = new Wire() { Name = a };
                }

                if (ushort.TryParse(b, out ushort bb))
                {
                    L2 = new Signal() { Value = bb };
                }
                else
                {
                    L2 = new Wire() { Name = b };
                }

                gate.L1 = L1;
                gate.L2 = L2;
                gate.Op = op.Key;

                break;
            }
        }
    }
}