feat: trying to solve part 2

05/IYGASAF.Tests/AlmanacTests.cs

@@ -2,8 +2,6 @@ namespace IYGASAF.Tests;
 
 public class AlmanacTests
 {
-  private readonly Almanac _sut = TestData.TestAlmanac;
-
   [Theory]
   [MemberData(nameof(TestData.TestAlmanacData), MemberType = typeof(TestData))]
   public void Parse_WhenGivenValidAlmanac_ItShouldReturnExpectedAlmanac(string[] almanac, Almanac expected)
@@ -19,17 +17,27 @@ public class AlmanacTests
   [InlineData(13, 35)]
   public void GetSeedLocation_WhenGivenValidSeed_ItShouldReturnExpectedLocation(int seed, int expected)
   {
-    var result = _sut.GetSeedLocation(seed);
+    var sut = TestData.TestAlmanac;
+    var result = sut.GetSeedLocation(seed);
     result.Should().Be(expected);
   }
 
   [Fact]
   public void GetLowestSeedLocation_WhenCalled_ItShouldReturnExpectedLocation()
   {
-    var result = _sut.GetLowestSeedLocation();
+    var sut = TestData.TestAlmanac;
+    var result = sut.GetLowestSeedLocation();
     result.Should().Be(35);
   }
 
+  [Fact]
+  public void GetLowestSeedLocation_WhenCalledAndSeedsAreParsedAsRanges_ItShouldReturnExpectedLocation()
+  {
+    var sut = Almanac.Parse(TestData.TestAlmanacInput);
+    var result = sut.GetLowestSeedLocation(true);
+    result.Should().Be(46);
+  }
+
   [Fact]
   public void GetLowestSeedLocation_WhenCalledWithPuzzleInput_ItShouldReturnExpectedLocation()
   {
@@ -39,6 +47,19 @@ public class AlmanacTests
     result.Should().Be(806029445);
   }
 
+  [Fact]
+  public void ParseSeedsAsRanges_WhenGivenValidSeedsString_ItShouldReturnExpectedSeeds()
+  {
+    var seedsString = "79 14 55 13";
+    var expected = new List<SeedRange>
+    {
+      new(79, 14),
+      new(55, 13),
+    };
+    var result = Almanac.ParseSeedsAsRanges(seedsString);
+    result.Should().BeEquivalentTo(expected);
+  }
+
   public static class TestData
   {
     public static readonly Almanac TestAlmanac =
@@ -49,6 +70,10 @@ public class AlmanacTests
           55,
           13,
         ],
+        [
+          new(79, 14),
+          new(55, 13),
+        ],
         [
           new(
             [
@@ -99,6 +124,36 @@ public class AlmanacTests
         ]
       );
 
+    public static readonly string[] TestAlmanacInput =
+      [
+        "seeds: 79 14 55 13",
+        "seed-to-soil map:",
+        "50 98 2",
+        "52 50 48",
+        "soil-to-fertilizer map:",
+        "0 15 37",
+        "37 52 2",
+        "39 0 15",
+        "fertilizer-to-water map:",
+        "49 53 8",
+        "0 11 42",
+        "42 0 7",
+        "57 7 4",
+        "water-to-light map:",
+        "88 18 7",
+        "18 25 70",
+        "light-to-temperature map:",
+        "45 77 23",
+        "81 45 19",
+        "68 64 13",
+        "temperature-to-humidity map:",
+        "0 69 1",
+        "1 0 69",
+        "humidity-to-location map:",
+        "60 56 37",
+        "56 93 4",
+      ];
+
     public static readonly IEnumerable<object[]> TestAlmanacData =
       new List<object[]>
       {

05/IYGASAF/Program.cs

@@ -18,7 +18,13 @@ public class Program
 
 
     var input = await File.ReadAllLinesAsync(args[0]);
-    var result = Almanac.Parse(input).GetLowestSeedLocation();
+    var seedsAreRanges = args.Length > 1 && args[1] == "part2";
+
+    Console.WriteLine("Parsing almanac...");
+    var almanac = Almanac.Parse(input);
+
+    Console.WriteLine("Getting lowest seed location...");
+    var result = almanac.GetLowestSeedLocation(seedsAreRanges);
 
     Console.WriteLine($"The lowest seed location is {result}.");
 
@@ -28,31 +34,99 @@ public class Program
 
 public class Almanac(
   List<long> seeds,
+  List<SeedRange> seedRanges,
   List<Map> maps
 )
 {
+  public List<SeedRange> SeedRanges { get; init; } = seedRanges;
   public List<long> Seeds { get; init; } = seeds;
   public List<Map> Maps { get; init; } = maps;
 
+  private static List<long> GetSeedsFromString(string seedsString) =>
+  seedsString
+    .Split(
+      ' ',
+      StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries
+    )
+    .Select(long.Parse)
+    .ToList();
+
   public long GetSeedLocation(long seed) => Maps.Aggregate(
     seed,
     (currentSeed, map) => map.ConvertSourceToDestination(currentSeed)
   );
 
-  public long GetLowestSeedLocation() => Seeds
-    .Select(GetSeedLocation)
-    .Min();
+  public class LocationResult
+  {
+    public long Value { get; set; } = long.MaxValue;
+  }
+
+  public long GetLowestSeedLocation(bool seedsAreRanges = false)
+  {
+    var lowestLocation = new LocationResult();
+
+    if (seedsAreRanges)
+    {
+      Parallel.ForEach(SeedRanges, (currentSeedRange) =>
+      {
+        var currentSeedRangeStart = currentSeedRange.Start;
+        var currentSeedRangeEnd = currentSeedRange.End;
+
+        for (long j = currentSeedRangeStart; j <= currentSeedRangeEnd; j++)
+        {
+          var currentSeed = j;
+          var currentSeedLocation = GetSeedLocation(currentSeed);
+
+          lock (lowestLocation)
+          {
+            if (currentSeedLocation < lowestLocation.Value)
+            {
+              lowestLocation.Value = currentSeedLocation;
+            }
+          }
+        }
+      });
+    }
+    else
+    {
+      for (int i = 0; i < Seeds.Count; i++)
+      {
+        var currentSeed = Seeds[i];
+        var currentSeedLocation = GetSeedLocation(currentSeed);
+
+        if (currentSeedLocation < lowestLocation.Value)
+        {
+          lowestLocation.Value = currentSeedLocation;
+        }
+      }
+    }
+
+    File.WriteAllText("output.txt", lowestLocation.Value.ToString());
+
+    return lowestLocation.Value;
+  }
+
+  public static List<SeedRange> ParseSeedsAsRanges(string seedsString)
+  {
+    var seeds = new List<SeedRange>();
+    var seedNumbers = GetSeedsFromString(seedsString);
+
+    for (int i = 0; i < seedNumbers.Count; i += 2)
+    {
+      var start = seedNumbers[i];
+      var length = seedNumbers[i + 1];
+
+      seeds.Add(new(start, length));
+    }
+
+    return seeds;
+  }
 
   public static Almanac Parse(string[] almanac)
   {
     var seedsString = almanac[0].Split(':')[1];
-    var seeds = seedsString
-      .Split(
-        ' ',
-        StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries
-      )
-      .Select(long.Parse)
-      .ToList();
+    var seeds = GetSeedsFromString(seedsString);
+    var seedRanges = ParseSeedsAsRanges(seedsString);
 
     var maps = new List<Map>();
     var ranges = new List<string>();
@@ -86,6 +160,7 @@ public class Almanac(
 
     return new Almanac(
       seeds,
+      seedRanges,
       maps
     );
   }
@@ -95,7 +170,7 @@ public class Map(
   List<Range> ranges
 )
 {
-  public List<Range> Ranges { get; init; } = ranges;
+  public List<Range> Ranges { get; init; } = [.. ranges.OrderBy(range => range.SourceStart)];
 
   public static Map Parse(string[] ranges) =>
     new(
@@ -124,6 +199,16 @@ public class Map(
   }
 }
 
+public class SeedRange(
+  long start,
+  long length
+)
+{
+  public long Start { get; init; } = start;
+  public long Length { get; init; } = length;
+  public long End => Start + Length - 1;
+}
+
 public class Range(
   long rangeLength,
   long sourceStart,