From a65d4fb1e8dc3c5690a2300bd89ff1dd0a4f7905 Mon Sep 17 00:00:00 2001
From: nin0dev <personal@nin0.dev>
Date: Mon, 2 Dec 2024 15:55:39 -0500
Subject: [PATCH] day 2

---
 .gitignore            |  7 +++-
 2024/README.md        |  2 +-
 2024/day2/Program.cs  | 79 +++++++++++++++++++++++++++++++++++++++++++
 2024/day2/example.txt |  6 ++++
 4 files changed, 92 insertions(+), 2 deletions(-)
 create mode 100644 2024/day2/Program.cs
 create mode 100644 2024/day2/example.txt

diff --git a/.gitignore b/.gitignore
index 8a15a0c..1040fc5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,8 @@
 testing/
 input.txt
-.idea/
\ No newline at end of file
+.idea/
+bin/
+obj/
+.vscode/
+*.sln
+*.csproj
\ No newline at end of file
diff --git a/2024/README.md b/2024/README.md
index 7910ee1..e72ef7f 100644
--- a/2024/README.md
+++ b/2024/README.md
@@ -14,7 +14,7 @@ AOC but one programming language per day
 - [ ] Dart
 - [ ] SQL
 - [ ] C
-- [ ] C#
+- [x] 2: C# (i get its meant to be used with visual studio but why make sooooo many meta files)
 - [x] 1: Kotlin (holy shit its actually a good lang)
 - [ ] PHP
 - [ ] JavaScript
diff --git a/2024/day2/Program.cs b/2024/day2/Program.cs
new file mode 100644
index 0000000..5e31a41
--- /dev/null
+++ b/2024/day2/Program.cs
@@ -0,0 +1,79 @@
+const int EXAMPLE_VALUE_1 = 2;
+const int EXAMPLE_VALUE_2 = 4;
+
+StreamReader inputFile;
+string input;
+
+Console.Write("Use (p)rod or (e)xample? > ");
+if (Console.ReadKey().Key == ConsoleKey.E) {
+    Console.WriteLine($"\nUsing example data, value should be of {EXAMPLE_VALUE_1} and {EXAMPLE_VALUE_2}");
+    inputFile = File.OpenText("example.txt");
+} else {
+    Console.WriteLine("\nUsing production data");
+    inputFile = File.OpenText("input.txt");
+}
+input = inputFile.ReadToEnd();
+
+string[] reports = input.Split("\n");
+List<string> invalidReports = [];
+Console.WriteLine($"{reports.Length} reports will be processed");
+
+int validReports = 0;
+
+static bool validateReport(List<int> levels) {
+    bool shouldBeIncreasing = levels[0] < levels[1];
+    bool hasIgnoredZeroIndex = false;
+
+    int lastNumber = levels[0];
+    foreach(var level in levels) {
+        if (levels.IndexOf(level) == 0 && !hasIgnoredZeroIndex) {
+            hasIgnoredZeroIndex = true;
+            continue;
+        }
+
+        if (lastNumber >= level && shouldBeIncreasing || lastNumber <= level && !shouldBeIncreasing) return false;
+        if (Math.Abs(lastNumber - level) > 3) return false;
+
+        lastNumber = level;
+    }
+    return true;
+}
+
+// Part 1
+foreach(var report in reports) {
+    string[] levelsAsString = report.Split(" ");
+    List <int> levels = [];
+
+    foreach(var levelAsString in levelsAsString) {
+        levels.Add(int.Parse(levelAsString));
+    }
+    if (validateReport(levels)) validReports++;
+    else {
+        invalidReports.Add(report);
+    }
+}
+
+Console.WriteLine($"Part 1: {validReports} valid reports!");
+
+// Part 2
+foreach(var report in invalidReports) {
+    string[] levelsAsString = report.Split(" ");
+    List <int> levels = [];
+
+    foreach(var levelAsString in levelsAsString) {
+        levels.Add(int.Parse(levelAsString));
+    }
+
+    for(var i = 0; i < levels.ToArray().Length; i++) {
+        List<int> manipulatedLevels = new(levels);
+        manipulatedLevels.RemoveAt(i);
+
+        if(validateReport(manipulatedLevels)) {
+            validReports++;
+            break;
+        }
+    }
+
+}
+
+Console.WriteLine($"Part 2: {validReports} valid reports!");
\ No newline at end of file
diff --git a/2024/day2/example.txt b/2024/day2/example.txt
new file mode 100644
index 0000000..82cd679
--- /dev/null
+++ b/2024/day2/example.txt
@@ -0,0 +1,6 @@
+7 6 4 2 1
+1 2 7 8 9
+9 7 6 2 1
+1 3 2 4 5
+8 6 4 4 1
+1 3 6 7 9
\ No newline at end of file