Initial Commit

2024/Day07CSharp/Program.cs

@@ -0,0 +1,98 @@
+// See https://aka.ms/new-console-template for more information
+using System.Collections.Generic;
+using System.Runtime.CompilerServices;
+
+var exParsed = new Day07Parsed("example-input.txt");
+
+Console.WriteLine("Example Part01: {0}", exParsed.GetPart01());
+Console.WriteLine("Example Part02: {0}", exParsed.GetPart02());
+
+var pzParsed = new Day07Parsed("puzzle-input.txt");
+
+Console.WriteLine("Puzzle Part01: {0}", pzParsed.GetPart01());
+Console.WriteLine("Puzzle Part02: {0}", pzParsed.GetPart02());
+
+class Day07Parsed : AdventCommon.ParsedInput
+{
+    class Equation
+    {
+        public long LeftHandSide { get; set; }
+        public List<long> RightHandSide { get; set; } = new List<int>();
+
+        public int MaxOpCount 
+        { 
+            get
+            {
+                return RightHandSide.Count - 1;
+            }
+        }
+
+        List<long> ValidOps { get; set; } = new List<long>();
+
+        public bool IsValid()
+        {
+            for (int i = 0; i < (int)Math.Pow(2,MaxOpCount); i++)
+            {
+                long eqTotal = RightHandSide[0];
+
+                // a value of 0 for a given bit is +, 1 is *
+                for (int opIndex = 0; opIndex < MaxOpCount; opIndex++)
+                {
+                    if ((i & (1 << opIndex)) == 0)
+                    {
+                        eqTotal += RightHandSide[opIndex + 1];
+                    } else
+                    {
+                        eqTotal *= RightHandSide[opIndex + 1];
+                    }
+
+                    if (eqTotal > LeftHandSide)
+                    {
+                        break;
+                    }
+                }
+
+                if (eqTotal == LeftHandSide)
+                {
+                    ValidOps.Add(i);
+                    return true;
+                }
+            }
+            return false;
+        }
+
+    }
+
+    public override int GetPart01()
+    {
+        int sum = 0;
+        foreach (var equation in Equations)
+        {
+            if (equation.IsValid())
+            {
+                sum += equation.LeftHandSide;
+            }
+        }
+        return 0;
+    }
+
+    List<Equation> Equations { get; set; } = new List<Equation>();
+
+    public Day07Parsed(string fileName) : base(fileName) { }
+
+    public override bool ParseLine(string line, object? context = null)
+    {
+        Equation equation = new Equation();
+
+        equation.LeftHandSide = Int32.Parse(line.Split(':')[0].Trim());
+
+        foreach (var v in line.Split(':')[1].Split(' ', StringSplitOptions.RemoveEmptyEntries))
+        {
+            equation.RightHandSide.Add(Int32.Parse(v));
+        }
+
+        Equations.Add(equation);
+
+        return true;
+    }
+}