From 60c80cf9466b3f1d8e9a7dbb984c177c03452c91 Mon Sep 17 00:00:00 2001
From: Folkert Kevelam <contact@pyllr.nl>
Date: Wed, 19 Mar 2025 20:08:32 +0100
Subject: [PATCH] Add solutions for day 3 part 1 and part 2

---
 AoC/2015/day_3/day_3.adb | 120 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 120 insertions(+)
 create mode 100644 AoC/2015/day_3/day_3.adb

diff --git a/AoC/2015/day_3/day_3.adb b/AoC/2015/day_3/day_3.adb
new file mode 100644
index 0000000..5928828
--- /dev/null
+++ b/AoC/2015/day_3/day_3.adb
@@ -0,0 +1,120 @@
+with Ada.Text_IO; use Ada.Text_IO;
+with Ada.Containers; use Ada.Containers;
+with Ada.Containers.Hashed_Sets;
+
+procedure Day_3 is
+
+    type Uint32 is mod 2**32;
+
+    type Coordinate is
+        record
+            X : Uint32;
+            Y : Uint32;
+        end record;
+
+    function "=" (A,B : Coordinate) return Boolean is
+    begin
+        return A.X = B.X and A.Y = B.Y;
+    end "=";
+
+    type Coordinates is array (Natural range <>) of Coordinate;
+
+    function Hash(A : Uint32) return Uint32 is
+        Key : Uint32 := A;
+    begin
+        Key := (not @) + (@ * 2**15);
+        Key := @ or (@ / 2**12);
+        Key := @ + (@ * 2**2);
+        Key := @ or (@ / 2**4);
+        Key := @ * 2057;
+        Key := @ or (Key / 2**16);
+        return Key;
+    end Hash;
+
+    function Hash(A : Coordinate) return Hash_Type is
+        Result : UInt32 := Hash((53 + Hash(A.X)) * 53 + Hash(A.Y));
+    begin
+        return Hash_Type(Integer(Result/2));
+    end Hash;
+
+    package Set is new Ada.Containers.Hashed_Sets(
+        Element_Type => Coordinate,
+        Hash => Hash,
+        Equivalent_Elements => "=");
+
+    function Read_File(File_Name : String) return Set.Set is
+        S : Set.Set;
+        Base : Coordinate := ( X => 0, Y => 0);
+        File : File_Type;
+    begin
+        S.Insert(Base);
+        Open(File, In_File, File_Name);
+
+        main_loop:
+        while not End_Of_File(File) loop
+            declare
+                Line : String := Get_Line(File);
+            begin
+                for I in Line'Range loop
+                    case Line(I) is
+                        when '^' => Base.Y := @ + 1;
+                        when 'v' => Base.Y := @ - 1;
+                        when '>' => Base.X := @ + 1;
+                        when '<' => Base.X := @ - 1;
+                        when others => exit main_loop;
+                    end case;
+                    if not S.Contains(Base) then
+                        S.Insert(Base);
+                    end if;
+                end loop;
+            end;
+        end loop main_loop;
+
+        Close(File);
+
+        return S;
+    end Read_File;
+
+    function Read_File_Part_Two(File_Name : String) return Set.Set is
+        S : Set.Set;
+        Base : Coordinates(0 .. 1) :=
+            (others => (X => 0, Y => 0));
+        File : File_Type;
+        Santa : Natural := 0;
+    begin
+        S.Insert(Base(0));
+        Open(File, In_File, File_Name);
+
+        main_loop:
+        while not End_Of_File(File) loop
+            declare
+                Line : String := Get_Line(File);
+            begin
+                for I in Line'Range loop
+                    case Line(I) is
+                        when '^' => Base(Santa).Y := @ + 1;
+                        when 'v' => Base(Santa).Y := @ - 1;
+                        when '>' => Base(Santa).X := @ + 1;
+                        when '<' => Base(Santa).X := @ - 1;
+                        when others => exit main_loop;
+                    end case;
+                    if not S.Contains(Base(Santa)) then
+                        S.Insert(Base(Santa));
+                    end if;
+                    Santa := (@ + 1) mod 2;
+                end loop;
+            end;
+        end loop main_loop;
+
+        Close(File);
+        return S;
+    end Read_File_Part_Two;
+
+    File_Name : String := "input_day_3.txt";
+    S : Set.Set;
+
+begin
+
+    Put_Line(Read_File_Part_Two(File_Name).Length'Image);
+
+end Day_3;