Files
advent-of-gode/2023/21/code.go
2023-12-22 16:27:22 +02:00

90 lines
2.3 KiB
Go

package main
import (
"fmt"
"strings"
"github.com/jpillora/puzzler/harness/aoc"
)
func main() {
aoc.Harness(run)
}
// on code change, run will be executed 4 times:
// 1. with: false (part1), and example input
// 2. with: true (part2), and example input
// 3. with: false (part1), and user input
// 4. with: true (part2), and user input
// the return value of each run is printed to stdout
func run(part2 bool, input string) any {
grid := make([][]rune, 0)
v, h := 0, 0
for y, l := range strings.Split(input, "\n") {
if l == "" {
continue
}
gridLine := make([]rune, 0)
for x, s := range strings.Split(l, "") {
if s == "S" {
v, h = y, x
}
gridLine = append(gridLine, rune(s[0]))
}
grid = append(grid, gridLine)
}
steps := 64
// when you're ready to do part 2, remove this "not implemented" block
if part2 {
return "not implemented"
}
// solve part 1 here
possibleCells := [][]int{{v, h}}
for i := 0; i < steps; i++ {
nextStepCells := make([][]int, 0)
alreadyStepped := make(map[string]bool)
for _, pc := range possibleCells {
if pc[0] > 0 && grid[pc[0]-1][pc[1]] != '#' {
if _, ok := alreadyStepped[fmt.Sprintf("%v;%v", pc[0]-1, pc[1])]; !ok {
nextStepCells = append(nextStepCells, []int{pc[0] - 1, pc[1]})
alreadyStepped[fmt.Sprintf("%v;%v", pc[0]-1, pc[1])] = true
}
}
if pc[1] > 0 && grid[pc[0]][pc[1]-1] != '#' {
if _, ok := alreadyStepped[fmt.Sprintf("%v;%v", pc[0], pc[1]-1)]; !ok {
nextStepCells = append(nextStepCells, []int{pc[0], pc[1] - 1})
alreadyStepped[fmt.Sprintf("%v;%v", pc[0], pc[1]-1)] = true
}
}
if pc[0] < len(grid)-1 && grid[pc[0]+1][pc[1]] != '#' {
if _, ok := alreadyStepped[fmt.Sprintf("%v;%v", pc[0]+1, pc[1])]; !ok {
nextStepCells = append(nextStepCells, []int{pc[0] + 1, pc[1]})
alreadyStepped[fmt.Sprintf("%v;%v", pc[0]+1, pc[1])] = true
}
}
if pc[1] < len(grid[0])-1 && grid[pc[0]][pc[1]+1] != '#' {
if _, ok := alreadyStepped[fmt.Sprintf("%v;%v", pc[0], pc[1]+1)]; !ok {
nextStepCells = append(nextStepCells, []int{pc[0], pc[1] + 1})
alreadyStepped[fmt.Sprintf("%v;%v", pc[0], pc[1]+1)] = true
}
}
}
possibleCells = nextStepCells
//fmt.Printf("Possible steps: %v\n", possibleCells)
}
return len(possibleCells)
}