Files
2019/main.go
Parnic effd94c09b Day 20 solution
Part 1 was pretty much just day 18 again, but without doors and with an input data parsing skill check. I simplified day 18 and went with a basic Dijkstra algorithm after the DFS to crawl the maze which solved this just fine.

Part 2 messed me up more than I was expecting. The key feature for part 2 is changing up what the Dijkstra solver views as an "adjacent" node and injecting the appropriate depth as we traverse inner/outer portals. The main thing that tripped me up here from part 1 was that I needed to be carrying more data along with portals than just their locations, and I could no longer get away with storing the portals as pairs of their inner/outer locations, so a small refactor was needed. Once I made those corrections, it was mostly a matter of ironing out the "get neighbors" function to adhere to part 2's rules, which took me a lot of debugging to get just right.

Part 2 still took me longer than I'd care to admit. I had problems wrapping my head around the problem.
2022-07-14 14:54:02 -05:00

152 lines
3.1 KiB
Go

package main
import (
"flag"
"fmt"
"log"
"os"
"runtime/pprof"
"strconv"
"strings"
"time"
"parnic.com/aoc2019/days"
"parnic.com/aoc2019/utilities"
)
type day interface {
Parse()
Num() int
Part1() string
Part2() string
}
const (
part1Header = utilities.ColorGreen + "Part1:" + utilities.TextReset
part2Header = utilities.ColorGreen + "Part2:" + utilities.TextReset
)
var (
flagPart1 = flag.Bool("part1", false, "whether to run part1 or not; if no flags are present, all parts are run")
flagPart2 = flag.Bool("part2", false, "whether to run part2 or not; if no flags are present, all parts are run")
flagCpuProfile = flag.String("cpuprofile", "", "write cpu profile to file")
flagMemProfile = flag.String("memprofile", "", "write memory profile to file")
)
var dayMap = []day{
&days.Day01{},
&days.Day02{},
&days.Day03{},
&days.Day04{},
&days.Day05{},
&days.Day06{},
&days.Day07{},
&days.Day08{},
&days.Day09{},
&days.Day10{},
&days.Day11{},
&days.Day12{},
&days.Day13{},
&days.Day14{},
&days.Day15{},
&days.Day16{},
&days.Day17{},
&days.Day18{},
&days.Day19{},
&days.Day20{},
}
func main() {
flag.Parse()
if *flagCpuProfile != "" {
f, err := os.Create(*flagCpuProfile)
if err != nil {
log.Fatal(err)
}
defer f.Close()
pprof.StartCPUProfile(f)
defer pprof.StopCPUProfile()
}
arg := strconv.Itoa(len(dayMap))
flagArgs := flag.Args()
if len(flagArgs) > 0 && len(flagArgs[0]) > 0 {
arg = flagArgs[0]
}
if strings.ToLower(arg) == "all" {
startTime := time.Now()
for _, v := range dayMap {
solve(v)
}
fmt.Printf("%sAll days completed in %v%s\n", utilities.ColorBrightBlack, time.Since(startTime), utilities.TextReset)
} else {
iArg, err := strconv.Atoi(arg)
if err != nil {
log.Fatalf("Invalid day " + utilities.ColorCyan + arg + utilities.TextReset)
}
if iArg < 0 || iArg > len(dayMap) {
log.Fatalf("Unknown day " + utilities.ColorCyan + arg + utilities.TextReset)
}
solve(dayMap[iArg-1])
}
if *flagMemProfile != "" {
f, err := os.Create(*flagMemProfile)
if err != nil {
log.Fatal(err)
}
pprof.WriteHeapProfile(f)
f.Close()
}
}
func solve(d day) {
fmt.Printf("%sDay %d%s\n", utilities.ColorCyan, d.Num(), utilities.TextReset)
fmt.Printf("----%s\n", strings.Repeat("-", len(strconv.Itoa(d.Num()))))
runPart1 := (!*flagPart1 && !*flagPart2) || *flagPart1
runPart2 := (!*flagPart1 && !*flagPart2) || *flagPart2
parseStart := time.Now()
d.Parse()
parseTime := time.Since(parseStart)
part1Start := time.Now()
var part1Text string
if runPart1 {
part1Text = d.Part1()
}
part1Time := time.Since(part1Start)
if runPart1 {
fmt.Println(part1Header)
fmt.Println(">", part1Text)
fmt.Println()
}
part2Start := time.Now()
var part2Text string
if runPart2 {
part2Text = d.Part2()
}
part2Time := time.Since(part2Start)
if runPart2 {
fmt.Println(part2Header)
fmt.Println(">", part2Text)
fmt.Println()
}
fmt.Print(utilities.ColorBrightBlack)
fmt.Println("Parsed in", parseTime)
if runPart1 {
fmt.Println("Part01 in", part1Time)
}
if runPart2 {
fmt.Println("Part02 in", part2Time)
}
fmt.Println(utilities.TextReset)
}