day 5

1 files changed, 74 insertions, 0 deletions

diff --git a/Day5.cs b/Day5.cs
new file mode 100644
index 0000000..3bbaa4c
--- /dev/null
+++ b/Day5.cs
@@ -0,0 +1,74 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+
+namespace aoc2019
+{
+    internal class Day5 : Day
+    {
+        public override int DayNumber => 5;
+
+        private static readonly IEnumerable<int> tape =
+            File.ReadLines("input/day5.in").First().Split(',').Select(int.Parse);
+
+        private static int output;
+        public static void RunIntCode(List<int> v, int input)
+        {
+            var i = 0;
+            while (i < v.Count && v[i] != 99)
+            {
+                int Val(int mode, int val) =>
+                    mode != 0 ? val : v[val];
+
+                var mode1 = v[i] / 100 % 10;
+                var mode2 = v[i] / 1000;
+
+                switch (v[i] % 100)
+                {
+                    case 1:
+                        v[v[i + 3]] = Val(mode1, v[i + 1]) + Val(mode2, v[i + 2]);
+                        i += 4;
+                        break;
+                    case 2:
+                        v[v[i + 3]] = Val(mode1, v[i + 1]) * Val(mode2, v[i + 2]);
+                        i += 4;
+                        break;
+                    case 3:
+                        v[v[i + 1]] = input;
+                        i += 2;
+                        break;
+                    case 4:
+                        output = Val(mode1, v[i + 1]);
+                        i += 2;
+                        break;
+                    case 5:
+                        i = Val(mode1, v[i + 1]) == 0 ? i + 3 : Val(mode2, v[i + 2]);
+                        break;
+                    case 6:
+                        i = Val(mode1, v[i + 1]) != 0 ? i + 3 : Val(mode2, v[i + 2]);
+                        break;
+                    case 7:
+                        v[v[i + 3]] = Val(mode1, v[i + 1]) < Val(mode2, v[i + 2]) ? 1 : 0;
+                        i += 4;
+                        break;
+                    case 8:
+                        v[v[i + 3]] = Val(mode1, v[i + 1]) == Val(mode2, v[i + 2]) ? 1 : 0;
+                        i += 4;
+                        break;
+                }
+            }
+        }
+        public override string Part1()
+        {
+            RunIntCode(tape.ToList(), 1);
+            return $"{output}";
+        }
+
+        public override string Part2()
+        {
+            RunIntCode(tape.ToList(), 5);
+            return $"{output}";
+        }
+    }
+}