solve day 2

aoc2021.test/DayTests.cs

@@ -5,6 +5,7 @@ public class DayTests
 {
     [DataTestMethod]
     [DataRow(typeof(Day01), "1616", "1645")]
+    [DataRow(typeof(Day02), "2272262", "2134882034")]
     public void CheckAllDays(Type dayType, string part1, string part2)
     {
         var s = Stopwatch.StartNew();
@@ -36,6 +37,7 @@ public class DayTests
     
     [DataTestMethod]
     [DataRow(typeof(Day01), "7", "5")]
+    [DataRow(typeof(Day02), "150", "900")]
     public void CheckTestInputs(Type dayType, string part1, string part2)
     {
         Day.UseTestInput = true;

aoc2021/Day02.cs

@@ -0,0 +1,60 @@
+namespace aoc2021;
+
+/// <summary>
+/// Day 2: <see href="https://adventofcode.com/2021/day/2"/>
+/// </summary>
+public sealed class Day02 : Day
+{
+    public Day02() : base(2, "Dive!")
+    {
+    }
+
+    public override string Part1()
+    {
+        int horiz = 0, depth = 0;
+        foreach (var line in Input)
+        {
+            var s = line.Split(' ');
+            var x = int.Parse(s[1]);
+            switch (s[0])
+            {
+                case "forward":
+                    horiz += x;
+                    break;
+                case "down":
+                    depth += x;
+                    break;
+                case "up":
+                    depth -= x;
+                    break;
+            }
+        }
+
+        return $"{horiz * depth}";
+    }
+
+    public override string Part2()
+    {
+        int aim = 0, depth = 0, horiz = 0;
+        foreach (var line in Input)
+        {
+            var s = line.Split(' ');
+            var x = int.Parse(s[1]);
+            switch (s[0])
+            {
+                case "forward":
+                    horiz += x;
+                    depth += aim * x;
+                    break;
+                case "down":
+                    aim += x;
+                    break;
+                case "up":
+                    aim -= x;
+                    break;
+            }
+        }
+
+        return $"{horiz * depth}";
+    }
+}

aoc2021/aoc2021.csproj

@@ -14,11 +14,11 @@
   </ItemGroup>
 
   <ItemGroup>
-    <Using Include="System.Collections.Generic"/>
-    <Using Include="System.Diagnostics"/>
-    <Using Include="System.Reflection"/>
-    <Using Include="System.Text"/>
-    <Using Include="System.Text.RegularExpressions"/>
+    <Using Include="System.Collections.Generic" />
+    <Using Include="System.Diagnostics" />
+    <Using Include="System.Reflection" />
+    <Using Include="System.Text" />
+    <Using Include="System.Text.RegularExpressions" />
   </ItemGroup>
 
 </Project>

aoc2021/input/test02.in

@@ -0,0 +1,6 @@
+forward 5
+down 5
+forward 8
+up 3
+down 8
+forward 2