Day 5

d05/main.odin

@@ -0,0 +1,85 @@
+package main
+
+import "core:math"
+import "core:slice"
+import "core:strconv"
+import "core:strings"
+import "core:bytes"
+import "core:fmt"
+import "core:os"
+
+import "../util"
+
+Row :: struct { min: i64, max: i64 }
+Column :: struct { min: i64, max: i64 }
+
+part_1 :: proc(lines: []string) {
+    result: i64 = 0
+
+    for line in lines {
+        row := Row{ min = 0, max = 127 }
+        col := Column{ min = 0, max = 7 }
+        for letter in line {
+            switch letter {
+            case 'B':
+                row.min += (row.max - row.min + 1) / 2
+            case 'F':
+                row.max -= (row.max - row.min + 1) / 2
+            case 'R':
+                col.min += (col.max - col.min + 1) / 2
+            case 'L':
+                col.max -= (col.max - col.min + 1) / 2
+            }
+        }
+
+        id := row.max * 8 + col.max
+        result = max(result, id)
+    }
+
+    fmt.printfln("Part 1: %d", result)
+}
+
+part_2 :: proc(lines: []string) {
+    result: i64 = 0
+    seats := [dynamic]i64{}
+
+    for line in lines {
+        row := Row{ min = 0, max = 127 }
+        col := Column{ min = 0, max = 7 }
+        for letter in line {
+            switch letter {
+            case 'B':
+                row.min += (row.max - row.min + 1) / 2
+            case 'F':
+                row.max -= (row.max - row.min + 1) / 2
+            case 'R':
+                col.min += (col.max - col.min + 1) / 2
+            case 'L':
+                col.max -= (col.max - col.min + 1) / 2
+            }
+        }
+        append(&seats, row.max * 8 + col.max)
+    }
+
+    slice.sort(seats[:])
+    for seat, idx in seats[1:len(seats)-1] {
+        if seat - 1 != seats[idx] {
+            result = seat - 1
+            break
+        }
+    }
+
+    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)
+}