Day 3

d03/main.odin

@@ -0,0 +1,74 @@
+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"
+
+part_1 :: proc(lines: []string) {
+    result := 0
+
+    right := 0
+    for line in lines {
+        if line[right] == '#' {
+            result += 1
+        }
+
+        right = (right + 3) % len(line)
+    }
+
+    fmt.printfln("Part 1: %d", result)
+}
+
+Slope :: struct {
+    right: i64,
+    down: i64,
+}
+
+part_2 :: proc(lines: []string) {
+    result: i64 = 1
+    
+    slopes := [?]Slope{
+        { right = 1, down = 1 },
+        { right = 3, down = 1 },
+        { right = 5, down = 1 },
+        { right = 7, down = 1 },
+        { right = 1, down = 2 },
+    }
+
+    for slope in slopes {
+        right: i64 = 0
+        trees_hit: i64 = 0
+
+        for line_idx: i64 = 0; line_idx < i64(len(lines)); line_idx += slope.down {
+            line := lines[line_idx] 
+            if line[right] == '#' {
+                trees_hit += 1
+            }
+
+            right = (right + slope.right) % i64(len(line))
+        }
+
+        result *= trees_hit
+    }
+
+    fmt.printfln("Part 2: %d", result)
+}
+
+main :: proc() {
+    context.allocator = context.temp_allocator
+
+    INPUT :: #load("input.txt", string)
+    lines := strings.split(INPUT, "\n")
+    lines = lines[:len(lines)-1]
+
+    part_1(lines)
+    part_2(lines)
+
+    free_all(context.temp_allocator)
+}