Day 11

.gitignore

@@ -1,2 +1,3 @@
 *.bin
 *.txt
+*.dSYM

d11/main.odin

@@ -0,0 +1,158 @@
+package main
+
+import "core:unicode/utf8"
+import "core:math"
+import "core:slice"
+import "core:strconv"
+import "core:strings"
+import "core:bytes"
+import "core:fmt"
+import "core:os"
+
+import "../util"
+
+is_inside_boundries :: proc(row_idx, col_idx: int, layout: [][]rune) -> bool {
+    return col_idx >= 0 && col_idx < len(layout[0]) && row_idx >= 0 && row_idx < len(layout)
+}
+
+get_adjacent_occupied :: proc(row_idx, col_idx: int, layout: [][]rune) -> i64 {
+    adjacent_occupied: i64 = 0
+
+    for adjacent_row_idx in -1..=1 {
+        for adjacent_col_idx in -1..=1 {
+            if adjacent_col_idx == 0 && adjacent_row_idx == 0 do continue
+
+            neighbour_row_idx := row_idx + adjacent_row_idx
+            neighbour_col_idx := col_idx + adjacent_col_idx
+
+            if is_inside_boundries(neighbour_row_idx, neighbour_col_idx, layout) && 
+                layout[neighbour_row_idx][neighbour_col_idx] == '#' {
+                    adjacent_occupied += 1
+                }
+            }
+        }
+
+    return adjacent_occupied
+}
+
+get_adjacent_visible :: proc(row_idx, col_idx: int, layout: [][]rune) -> i64 {
+    visible_occupied: i64 = 0
+
+    directions := [8]struct{dr, dc: int}{
+        {-1, -1}, {-1, 0}, {-1, 1}, 
+        { 0, -1}, { 0, 1},         
+        { 1, -1}, { 1, 0}, { 1, 1},  
+    }
+    for dir in directions {
+        r, c := row_idx + dir.dr, col_idx + dir.dc 
+        
+        for is_inside_boundries(r, c, layout) {
+            tile := layout[r][c]
+            
+            if tile == '#' {
+                visible_occupied += 1
+                break
+            } else if tile == 'L' {
+                break 
+            }
+            
+            r += dir.dr
+            c += dir.dc
+        }
+    }
+
+    return visible_occupied
+}
+
+part_1 :: proc(lines: []string) {
+    result: i64 = 0
+
+    layout := slice.mapper(lines, proc(line: string) -> []rune {
+        return utf8.string_to_runes(line)
+    })
+
+    changed := true 
+    for changed {
+        new_layout := slice.clone(layout) 
+        for row, row_idx in layout do new_layout[row_idx] = slice.clone(row)
+        changed = false
+
+        for row, row_idx in layout {
+            for tile, col_idx in row {
+                if tile == '#' {
+                    adjacent_occupied := get_adjacent_occupied(row_idx, col_idx, layout) 
+                    if adjacent_occupied >= 4 {
+                        new_layout[row_idx][col_idx] = 'L'
+                        changed = true
+                    }
+                } else if tile == 'L' {
+                    adjacent_occupied := get_adjacent_occupied(row_idx, col_idx, layout) 
+                    if adjacent_occupied == 0 {
+                        new_layout[row_idx][col_idx] = '#'
+                        changed = true
+                    }
+                }
+            }
+        }
+
+        layout = new_layout
+    }
+
+
+    result = slice.reduce(layout, i64(0), proc(res: i64, row: []rune) -> i64 {
+        return res + i64(slice.count(row, '#'))
+    })
+    fmt.printfln("Part 1: %d", result)
+}
+
+part_2 :: proc(lines: []string) {
+    result: i64 = 0
+
+    layout := slice.mapper(lines, proc(line: string) -> []rune {
+        return utf8.string_to_runes(line)
+    })
+
+    changed := true 
+    for changed {
+        new_layout := slice.clone(layout) 
+        for row, row_idx in layout do new_layout[row_idx] = slice.clone(row)
+        changed = false
+
+        for row, row_idx in layout {
+            for tile, col_idx in row {
+                if tile == '#' {
+                    adjacent_occupied := get_adjacent_visible(row_idx, col_idx, layout) 
+                    if adjacent_occupied >= 5 {
+                        new_layout[row_idx][col_idx] = 'L'
+                        changed = true
+                    }
+                } else if tile == 'L' {
+                    adjacent_occupied := get_adjacent_visible(row_idx, col_idx, layout) 
+                    if adjacent_occupied == 0 {
+                        new_layout[row_idx][col_idx] = '#'
+                        changed = true
+                    }
+                }
+            }
+        }
+
+        layout = new_layout
+    }
+
+    result = slice.reduce(layout, i64(0), proc(res: i64, row: []rune) -> i64 {
+        return res + i64(slice.count(row, '#'))
+    })
+    fmt.printfln("Part 2: %d", result)
+}
+
+main :: proc() {
+    context.allocator = context.temp_allocator
+    defer free_all(context.temp_allocator)
+
+    INPUT :: #load("input.txt", string)
+    lines := strings.split(INPUT, "\n")
+    lines = lines[:len(lines)-1]
+
+    part_1(lines)
+    part_2(lines)
+}