Files
aoc-2025/day01/source/day01.swift
2025-12-12 21:56:14 -05:00

142 lines
3.3 KiB
Swift

#if !hasFeature(Embedded)
import Foundation
#endif
@main
struct Day01 {
static func run() {
guard let input = realInput else {
print("input sttring nil")
return
}
print("Started...")
let parsed = parseInput(input)
part1(parsed)
part2(parsed)
print("Press Start to exit...")
}
static func parseInput(_ input: String) -> [(Direction, Int)] {
input.split(separator: "\n").map({ line in
return (
Direction(line.first!),
Int(line.dropFirst())!
)
})
}
static func part1(_ input: [(Direction, Int)]) {
var cur = 50
var count = 0
for (dir, num) in input {
cur = switch dir {
case .Left: (cur - num) % 100
case .Right: (cur + num) % 100
}
if (cur < 0) { cur += 100 }
if (cur == 0) { count += 1 }
}
print("Part 1: \(count)")
}
static func part2(_ input: [(Direction, Int)]) {
var cur = 50
var count = 0
for (dir, num) in input {
let start = cur
let fullCycles = num - (num % 100)
count += fullCycles / 100
cur = switch dir {
case .Left: (cur - num) % 100
case .Right: (cur + num) % 100
}
if (cur < 0) { cur += 100 }
switch dir {
case .Left:
if (start - (num % 100)) < 0 && start != 0 {
count += 1
}
case .Right:
if (start + (num % 100)) >= 100 && start != 0 && cur != 0 {
count += 1
}
}
if (cur == 0) { count += 1 }
}
print("Part 2: \(count)")
}
#if hasFeature(Embedded)
static func main() {
gfxInitDefault()
consoleInit(GFX_TOP, nil)
guard romfsInit() == 0 else {
print("Couldn't init RomFS")
return
}
testInput = stringFromFile("romfs:/test.txt")
realInput = stringFromFile("romfs:/input.txt")
run()
while aptMainLoop() {
hidScanInput()
let kDown = hidKeysDown()
if kDown & KEY_START != 0 {
break
}
gfxFlushBuffers()
gfxSwapBuffers()
}
gfxExit()
}
static func stringFromFile(_ path: String) -> String {
let file = fopen(path, "r")
var ret = ""
var buf = [CChar](repeating: 0, count: 100)
while fgets(&buf, 100, file) != nil {
ret += String(cString: buf)
}
guard feof(file) != 0 else {
print("Error reading file \(path)")
return ""
}
return ret
}
#else
static func main() {
testInput = try? String(contentsOfFile: "romfs/test.txt")
realInput = try? String(contentsOfFile: "romfs/input.txt")
run()
}
#endif
}
enum Direction {
case Left
case Right
init(_ char: Character) {
self = switch char {
case "L": Direction.Left
case "R": Direction.Right
default: fatalError()
}
}
}
var testInput: String? = nil
var realInput: String? = nil