aoc25/d07/main.odin
2025-12-07 12:17:54 +01:00

90 lines
2.1 KiB
Odin

package main
import "core:container/queue"
import "core:fmt"
import "core:math"
import "core:math/linalg"
import "core:os"
import "core:slice"
import "core:strconv"
import "core:strings"
import "core:time"
import "core:unicode/utf8"
import util "../util"
Vec2 :: [2]int
count_paths :: proc(pos: Vec2, lines: []string, cache: ^map[Vec2]i64) -> i64 {
if pos.y >= len(lines) do return 1
if cached, ok := cache[pos]; ok do return cached
result: i64 = 0
switch lines[pos.y][pos.x] {
case '^':
result =
count_paths(Vec2{pos.x - 1, pos.y + 1}, lines, cache) +
count_paths(Vec2{pos.x + 1, pos.y + 1}, lines, cache)
case:
result = count_paths(Vec2{pos.x, pos.y + 1}, lines, cache)
}
cache[pos] = result
return result
}
part_1 :: proc(lines: []string) {
result: i64 = 0
start_x, _ := slice.linear_search(transmute([]u8)lines[0], 'S')
stack := make([dynamic]Vec2)
visited := make(map[Vec2]struct{})
append(&stack, Vec2{start_x, 0})
for len(stack) > 0 {
pos := pop(&stack)
if pos.y >= len(lines) do continue
if pos in visited do continue
visited[pos] = {}
switch lines[pos.y][pos.x] {
case '^':
append(&stack, Vec2{pos.x - 1, pos.y + 1})
append(&stack, Vec2{pos.x + 1, pos.y + 1})
result += 1
case:
append(&stack, Vec2{pos.x, pos.y + 1})
}
}
fmt.printfln(" [Result] %v", result)
}
part_2 :: proc(lines: []string) {
cache := make(map[Vec2]i64)
start_x, _ := slice.linear_search(transmute([]u8)lines[0], 'S')
result := count_paths(Vec2{start_x, 0}, lines, &cache)
fmt.printfln(" [Result] %v", 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]
fmt.println("[Part 1]")
start := time.tick_now()
part_1(lines)
duration := time.tick_diff(start, time.tick_now())
fmt.printfln(" [Time] %vms\n", time.duration_milliseconds(duration))
fmt.printfln("[Part 2]")
start = time.tick_now()
part_2(lines)
duration = time.tick_diff(start, time.tick_now())
fmt.printfln(" [Time] %vms", time.duration_milliseconds(duration))
}