/
day25.go
90 lines (83 loc) · 1.38 KB
/
day25.go
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package main
import (
"fmt"
"os"
"strings"
)
func day25file() string {
data, err := os.ReadFile("input/day25.txt")
if err != nil {
panic(err)
}
return string(data)
}
func day25a(input string) int {
width := strings.Index(input, "\n")
grid := []byte(strings.ReplaceAll(input, "\n", ""))
height := len(grid) / width
step := 0
render := func() {
for i := range grid {
if i%width == 0 {
fmt.Println()
if i == 0 {
fmt.Println("step", step)
}
}
fmt.Printf("%c", grid[i])
}
fmt.Println()
}
_ = render
for {
step++
newgrid := make([]byte, len(grid))
copy(newgrid, grid)
var moves int
for i, v := range grid {
if v != '>' {
continue
}
row := i / width
col := i%width + 1
if col >= width {
col = 0
}
if idx := row*width + col; grid[idx] == '.' {
newgrid[i] = '.'
newgrid[idx] = '>'
moves++
}
}
copy(grid, newgrid)
for i, v := range grid {
if v != 'v' {
continue
}
row := i/width + 1
if row >= height {
row = 0
}
col := i % width
if idx := row*width + col; grid[idx] == '.' {
newgrid[i] = '.'
newgrid[idx] = 'v'
moves++
}
}
grid = newgrid
// render()
if moves == 0 {
break
}
}
return step
}
func Day25a() {
result := day25a(day25file())
fmt.Println("day 25a:", result)
}
func Day25() {
result := day25a(day25file())
fmt.Println("day 25:", result)
}