From 5a2f2af56147b1245f72d973c1935c46e451fe33 Mon Sep 17 00:00:00 2001
From: Greg Burri <greg.burri@gmail.com>
Date: Thu, 14 Dec 2017 20:50:42 +0100
Subject: [PATCH] Day 15 template

---
 AdventOfCode2017/AdventOfCode2017.fsproj |  9 +++++++-
 AdventOfCode2017/Day15.fs                | 26 ++++++++++++++++++++++++
 AdventOfCode2017/Program.fs              | 10 ++++++---
 Tests/Day15 tests.fs                     | 17 ++++++++++++++++
 Tests/Tests.fsproj                       |  1 +
 5 files changed, 59 insertions(+), 4 deletions(-)
 create mode 100644 AdventOfCode2017/Day15.fs
 create mode 100644 Tests/Day15 tests.fs

diff --git a/AdventOfCode2017/AdventOfCode2017.fsproj b/AdventOfCode2017/AdventOfCode2017.fsproj
index 436c8cf..f2d6bcc 100644
--- a/AdventOfCode2017/AdventOfCode2017.fsproj
+++ b/AdventOfCode2017/AdventOfCode2017.fsproj
@@ -25,7 +25,7 @@
     <PlatformTarget>AnyCPU</PlatformTarget>
     <DocumentationFile>bin\$(Configuration)\$(AssemblyName).XML</DocumentationFile>
     <Prefer32Bit>true</Prefer32Bit>
-    <StartArguments>14</StartArguments>
+    <StartArguments>15</StartArguments>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
     <DebugType>pdbonly</DebugType>
@@ -71,6 +71,7 @@
     <Compile Include="Day13.fs" />
     <Compile Include="Day14.fs" />
     <Compile Include="Day14Compact.fs" />
+    <Compile Include="Day15.fs" />
     <Compile Include="Program.fs" />
     <None Include="App.config" />
     <Content Include="Data\day1.input">
@@ -106,6 +107,12 @@
     <Content Include="Data\day13.input">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>
+    <Content Include="Data\day14.input">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+    <Content Include="Data\day15.input">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
     <Content Include="packages.config" />
   </ItemGroup>
   <ItemGroup>
diff --git a/AdventOfCode2017/Day15.fs b/AdventOfCode2017/Day15.fs
new file mode 100644
index 0000000..96bc829
--- /dev/null
+++ b/AdventOfCode2017/Day15.fs
@@ -0,0 +1,26 @@
+module AdventOfCode2017.Day15
+
+let hash = Day10.knotHash2Encoding (fun i -> System.Convert.ToString(i, 2).PadLeft(8, '0'))
+
+let buildMatrix (input : string) =
+    let mat = Array2D.zeroCreate 128 128
+    for i = 0 to 127 do
+        input + "-" + (string i) |> hash |> Seq.iteri (fun j c -> mat.[i, j] <- int c - int '0')
+    mat
+
+let nbOfUsedSquares (input : string) =
+    let mutable i = 0
+    buildMatrix input |> Array2D.iter (fun b -> i <- i + b)
+    i
+
+let nbOfConnectedRegions (input : string) =
+    let m = buildMatrix input
+
+    let rec remove i j =
+        if i >= 0 && i < 128 && j >= 0 && j < 128 && m.[i, j] = 1 then
+            m.[i, j] <- 0
+            1 + remove (i + 1) j * remove (i - 1) j * remove i (j + 1) * remove i (j - 1)
+        else
+            0
+
+    [ for i in 0 .. 127 do for j in 0 .. 127 -> remove i j ] |> List.sum
\ No newline at end of file
diff --git a/AdventOfCode2017/Program.fs b/AdventOfCode2017/Program.fs
index 0c14451..0c6b4de 100644
--- a/AdventOfCode2017/Program.fs
+++ b/AdventOfCode2017/Program.fs
@@ -63,9 +63,12 @@ let day13 () =
     sprintf "part1 = %A, part2 = %A" part1 part2
 
 let day14 () =
-    let part1 = Day14.nbOfUsedSquares "hwlqcszp"
-    let part2 = Day14.nbOfConnectedRegions "hwlqcszp"
-    sprintf "part1 = %A, part2 = %A" part1 part2
+    let input = File.ReadAllText "Data/day14.input"
+    sprintf "part1 = %A, part2 = %A" (Day14.nbOfUsedSquares input) (Day14.nbOfConnectedRegions input)
+
+let day15 () =
+    let input = File.ReadAllText "Data/day15.input"
+    sprintf "part1 = %A, part2 = %A" () ()
 
 let doDay (n : int) =
     let sw = Diagnostics.Stopwatch ()
@@ -86,6 +89,7 @@ let doDay (n : int) =
         | 12 -> day12 ()
         | 13 -> day13 ()
         | 14 -> day14 ()
+        | 15 -> day15 ()
         | _ -> raise <| NotImplementedException ()
     printfn "Result of day %i: %s (time : %i ms)" n result sw.ElapsedMilliseconds
 
diff --git a/Tests/Day15 tests.fs b/Tests/Day15 tests.fs
new file mode 100644
index 0000000..cad5296
--- /dev/null
+++ b/Tests/Day15 tests.fs	
@@ -0,0 +1,17 @@
+namespace AdventOfCode2017.Tests
+
+open Xunit
+open Xunit.Abstractions
+open Swensen.Unquote
+
+open AdventOfCode2017
+
+type ``Day15 tests`` (output : ITestOutputHelper) =
+
+    [<Fact>]
+    let ``(Part1) From web page`` () =
+        ()
+
+    [<Fact>]
+    let ``(Part2) From web page`` () =
+        ()
\ No newline at end of file
diff --git a/Tests/Tests.fsproj b/Tests/Tests.fsproj
index 3b76237..96bd24e 100644
--- a/Tests/Tests.fsproj
+++ b/Tests/Tests.fsproj
@@ -69,6 +69,7 @@
     <Compile Include="Day12 tests.fs" />
     <Compile Include="Day13 tests.fs" />
     <Compile Include="Day14 tests.fs" />
+    <Compile Include="Day15 tests.fs" />
     <Content Include="packages.config" />
     <Content Include="App.config" />
   </ItemGroup>
-- 
2.45.2