From adfbbf1b0a91211ce6cf5e3fe26736573c8b750d Mon Sep 17 00:00:00 2001
From: Ben Harris <ben@tilde.team>
Date: Wed, 20 Sep 2023 13:22:48 -0400
Subject: [PATCH] 2015 day 17

---
 AOC.Test/Test2015.cs |  1 +
 AOC2015/Day17.cs     | 15 +++++++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/AOC.Test/Test2015.cs b/AOC.Test/Test2015.cs
index a730cf5..7a2ecf3 100644
--- a/AOC.Test/Test2015.cs
+++ b/AOC.Test/Test2015.cs
@@ -22,6 +22,7 @@ public class Test2015
     [DataRow(typeof(Day14), "2655", "1059")]
     [DataRow(typeof(Day15), "222870", "117936")]
     [DataRow(typeof(Day16), "103", "405")]
+    [DataRow(typeof(Day17), "1304", "18")]
     public void CheckAllDays(Type dayType, string part1, string part2)
     {
         Common.CheckDay(dayType, part1, part2);
diff --git a/AOC2015/Day17.cs b/AOC2015/Day17.cs
index 54df631..83ac83b 100644
--- a/AOC2015/Day17.cs
+++ b/AOC2015/Day17.cs
@@ -5,15 +5,26 @@ namespace AOC2015;
 /// </summary>
 public sealed class Day17 : Day
 {
+    private List<int>? _containers;
+    private IEnumerable<List<int>>? _combinations;
+
     public Day17() : base(2015, 17, "No Such Thing as Too Much")
     {
     }
     
     public override void ProcessInput()
     {
+        _containers = Input.Select(int.Parse).ToList();
+        _combinations = Enumerable.Range(1, (1 << _containers.Count) - 1)
+            .Select(i => _containers.Where((_, index) => ((1 << index) & i) != 0).ToList());
     }
 
-    public override object Part1() => "";
+    public override object Part1() => _combinations!.Count(c => c.Sum() == 150);
 
-    public override object Part2() => "";
+    public override object Part2()
+    {
+        var successfulCombinations = _combinations!.Where(c => c.Sum() == 150).ToList();
+        var minCount = successfulCombinations.Min(c => c.Count);
+        return successfulCombinations.Count(c => c.Count == minCount);
+    }
 }