From 2c6c7c81af39bf79e660e72790576a5e90dab633 Mon Sep 17 00:00:00 2001
From: plasmaofthedawn <plasmaofthedawn@gmail.com>
Date: Sat, 23 Dec 2023 09:43:27 -0500
Subject: [PATCH] day 14 part 2

---
 resources/day14sample.txt |   1 -
 src/day14/part2.pas       | 290 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 290 insertions(+), 1 deletion(-)
 create mode 100644 src/day14/part2.pas

diff --git a/resources/day14sample.txt b/resources/day14sample.txt
index f1105f8..b92d1a3 100644
--- a/resources/day14sample.txt
+++ b/resources/day14sample.txt
@@ -1,4 +1,3 @@
-##########
 O....#....
 O.OO#....#
 .....##...
diff --git a/src/day14/part2.pas b/src/day14/part2.pas
new file mode 100644
index 0000000..09cdfd7
--- /dev/null
+++ b/src/day14/part2.pas
@@ -0,0 +1,290 @@
+{$mode objfpc}
+{$RANGECHECKS ON}
+
+program day14part1;
+uses sysutils;
+
+procedure print_map(map: array of string; height: int32);
+var
+    i: int32;
+begin
+    for i := 0 to height - 1 do
+        writeln(map[i]);
+end;
+
+procedure copy_map(map: array of string; var map2: array of string; height: int32);
+var
+    i: int32;
+begin
+    for i := 0 to height - 1 do
+        map2[i] := map[i]
+end;
+
+procedure shift_up(var map: array of string; height: int32; width: int32);
+var
+    i, j, k: int32;
+    current_boulders: int32;
+begin
+    for i := 1 to width do
+    begin
+
+        current_boulders := 0;
+
+        for j := 1 to height do
+        begin
+            case map[height - j][i] of
+                'O':
+                begin
+                    current_boulders := current_boulders + 1;
+                    map[height - j][i] := '.'
+                end;
+                '#':
+                begin
+                    for k := height - j + 1 to height - j + current_boulders do
+                    begin
+                        map[k][i] := 'O'
+                    end;
+                    current_boulders := 0;
+                end;
+            end;
+        end;
+
+        for k := 0 to current_boulders - 1 do
+        begin
+            map[k][i] := 'O'
+        end;
+        current_boulders := 0;
+
+    end;
+end;
+
+procedure shift_left(var map: array of string; height: int32; width: int32);
+var
+    i, j, k: int32;
+    current_boulders: int32;
+begin
+    for i := 0 to height - 1 do
+    begin
+
+        current_boulders := 0;
+
+        for j := 0 to width - 1 do
+        begin
+            case map[i][width - j] of
+                'O':
+                begin
+                    current_boulders := current_boulders + 1;
+                    map[i][width - j] := '.'
+                end;
+                '#':
+                begin
+                    for k := width - j + 1 to width - j + current_boulders do
+                    begin
+                        map[i][k] := 'O'
+                    end;
+                    current_boulders := 0;
+                end;
+            end;
+        end;
+
+        for k := 1 to current_boulders do
+        begin
+            map[i][k] := 'O'
+        end;
+        current_boulders := 0;
+
+    end;
+end;
+
+procedure shift_down(var map: array of string; height: int32; width: int32);
+var
+    i, j, k: int32;
+    current_boulders: int32;
+begin
+    for i := 1 to width do
+    begin
+
+        current_boulders := 0;
+
+        for j := 0 to height - 1 do
+        begin
+            case map[j][i] of
+                'O':
+                begin
+                    current_boulders := current_boulders + 1;
+                    map[j][i] := '.'
+                end;
+                '#':
+                begin
+                    for k := j - current_boulders to j - 1 do
+                    begin
+                        map[k][i] := 'O'
+                    end;
+                    current_boulders := 0;
+                end;
+            end;
+        end;
+
+        for k := height - current_boulders to height - 1 do
+        begin
+            map[k][i] := 'O'
+        end;
+        current_boulders := 0;
+
+    end;
+end;
+
+procedure shift_right(var map: array of string; height: int32; width: int32);
+var
+    i, j, k: int32;
+    current_boulders: int32;
+begin
+    for i := 0 to height - 1 do
+    begin
+
+        current_boulders := 0;
+
+        for j := 1 to width do
+        begin
+            case map[i][j] of
+                'O':
+                begin
+                    current_boulders := current_boulders + 1;
+                    map[i][j] := '.'
+                end;
+                '#':
+                begin
+                    for k := j - current_boulders to j - 1 do
+                    begin
+                        map[i][k] := 'O'
+                    end;
+                    current_boulders := 0;
+                end;
+            end;
+        end;
+
+        for k := width - current_boulders + 1 to width do
+        begin
+            map[i][k] := 'O'
+        end;
+        current_boulders := 0;
+
+    end;
+end;
+
+procedure spin_cycle(var map: array of string; height: int32; width: int32);
+begin
+    shift_up(map, height, width);
+    shift_left(map, height, width);
+    shift_down(map, height, width);
+    shift_right(map, height, width);
+end;
+
+function calculate_load(map: array of string; height: int32): int32;
+var
+    i: int32;
+    c: char;
+begin
+    calculate_load := 0;
+    for i := 0 to height - 1 do
+    begin
+        for c in map[i] do
+        begin
+            if c = 'O' then
+                calculate_load := calculate_load + height - i;
+        end;
+    end;
+end;
+
+function strcomp(s1: string; s2: string): boolean;
+var
+    i: int32;
+begin
+    strcomp := true;
+    for i := 1 to length(s1) do
+    begin
+        if (s1[i] <> s2[i]) then
+        begin
+            strcomp := false;
+            break;
+        end;
+    end;
+end;
+
+function map_equal(map: array of string; map2: array of string; height: int32): boolean;
+var
+    i: int32;
+begin
+    map_equal := true;
+    for i := 0 to height - 1 do
+    begin
+        if not strcomp(map[i], map2[i]) then
+        begin
+            map_equal := false;
+            break;
+        end;
+    end;
+end;
+
+var
+
+    file_: text;
+
+    map: array[1..10000, 1..100] of string;
+    values: array[1..10000] of int32;
+    
+    height, width: int32;
+    i, j: int32;
+
+    finished: boolean;
+
+    wanted: int32;
+
+begin
+
+    assign(file_, 'resources/day14.txt');
+    reset(file_);
+
+    height := 0;
+
+    while not eof(file_) do
+    begin
+        height := height + 1;
+        readln(file_, map[1, height]);
+    end;
+
+    width := length(map[1, 1]);
+    values[1] := calculate_load(map[1], height);
+    finished := false;
+
+    for i := 2 to 100000 do
+    begin
+
+        copy_map(map[i - 1], map[i], height);
+        spin_cycle(map[i], height, width);
+        values[i] := calculate_load(map[i], height);
+
+        writeln('Found value ', values[i], ' for the ', i, 'th spin cycle');
+
+        for j := 1 to i - 1 do
+        begin
+            if map_equal(map[i], map[j], height) then
+            begin
+                writeln('This map is equal to the ', j, 'th map');
+                finished := true;
+                break;
+            end;
+        end;
+
+        if finished then
+            break;
+
+    end;
+
+    wanted := 1000000000;
+
+    writeln('This map has a cycle length of ', i - j, 'x + ', j);
+    writeln('This places ', wanted, ' at position ', (wanted - j) mod (i - j) + j + 1, ' in the cycle');
+    writeln('It would have a total load of ', values[(wanted - j) mod (i - j) + j + 1]);
+
+end.