From 85314237dd92db15a8dbd4f9aa9ed391333461c5 Mon Sep 17 00:00:00 2001
From: Folkert Kevelam <contact@pyllr.nl>
Date: Tue, 25 Feb 2025 21:46:47 +0100
Subject: [PATCH] Solve day 2 part 1

---
 AoC/2024/day_2/day_2.adb | 134 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 134 insertions(+)
 create mode 100644 AoC/2024/day_2/day_2.adb

diff --git a/AoC/2024/day_2/day_2.adb b/AoC/2024/day_2/day_2.adb
new file mode 100644
index 0000000..61e22d8
--- /dev/null
+++ b/AoC/2024/day_2/day_2.adb
@@ -0,0 +1,134 @@
+with Ada.Text_IO; use Ada.Text_IO;
+with Ada.Containers.Vectors;
+
+procedure Day_2 is
+
+    type Levels is array (Natural range <> ) of Integer;
+
+    type Ordering is (Increasing, Decreasing);
+
+    type Safety is (Safe, Unsafe);
+
+    type Report is
+        record
+            Values : Levels(0 .. 9);
+            Count : Natural := 0;
+        end record;
+
+    type Reports is array (Natural range <>) of Report;
+
+    function Calculate_Report( R : Report ) return Safety is
+        Order : Ordering;
+    begin
+        if R.Count > 1 then
+            if R.Values(1) > R.Values(0) then
+                Order := Increasing;
+            elsif R.Values(1) < R.Values(0) then
+                Order := Decreasing;
+            else
+                return Unsafe;
+            end if;
+        else
+            return Unsafe;
+        end if;
+
+        for I in 1 .. R.Count - 1 loop
+            declare
+                Diff : Integer := R.Values(I) - R.Values(I-1);
+                Adiff : Integer := abs(Diff);
+            begin
+                if ADiff < 1 or ADiff > 3 then
+                    return Unsafe;
+                elsif Diff > 0 and Order = Decreasing then
+                    return Unsafe;
+                elsif Diff < 0 and Order = Increasing then
+                    return Unsafe;
+                end if;
+            end;
+        end loop;
+
+        return Safe;
+    end Calculate_Report;
+
+    function Get_Safe_Reports( R : Reports ) return Natural is
+        Sum : Natural := 0;
+    begin
+        for Rep of R loop
+            declare
+                Result : Safety := Calculate_Report(Rep);
+            begin
+                if Result = Safe then
+                    Sum := @ + 1;
+                end if;
+            end;
+        end loop;
+
+        return Sum;
+    end Get_Safe_Reports;
+
+    function ToNum( Num : String ) return Integer is
+    begin
+        return Integer'Value(Num);
+    end ToNum;
+
+    function Read_Report( Line : String ) return Report is
+        In_Num : Boolean := False;
+        Start_Num : Natural;
+        Result : Report;
+    begin
+        for I in Line'Range loop
+            case Line(I) is
+                when '-' | '0' .. '9' =>
+                    if not In_Num then
+                        In_Num := True;
+                        Start_Num := I;
+                    end if;
+                when others =>
+                    if In_Num then
+                        Result.Values(Result.Count) :=
+                            ToNum(Line(Start_Num .. I-1));
+                        Result.Count := @ + 1;
+                        In_Num := False;
+                    end if;
+            end case;
+        end loop;
+
+        if In_Num then
+            Result.Values(Result.Count) :=
+                ToNum(Line(Start_Num .. Line'Last));
+            Result.Count := @ + 1;
+        end if;
+
+        return Result;
+    end Read_Report;
+
+    function Read_File( File_Name : String ) return Reports is
+        File : File_Type;
+
+        package vec is new
+            Ada.Containers.Vectors( Natural, Report );
+
+        use vec;
+
+        Result : vec.Vector;
+
+    begin
+        Open( File, In_File, File_Name );
+        while not End_Of_File(File) loop
+            Result.Append(Read_Report(Get_Line(File)));
+        end loop;
+
+        Close( File);
+
+        return R : Reports( 0 .. Natural(Result.Length) - 1) do
+            for I in Result.First_Index .. Result.Last_Index loop
+                R(Natural(I)) := Result(Natural(I));
+            end loop;
+        end return;
+    end Read_File;
+
+    File_Name : String := "input_day_2.txt";
+
+begin
+    Put_Line("Day 2 1:" & Get_Safe_Reports(Read_File(File_Name))'Image);
+end Day_2;