70 lines
1.2 KiB
Go

package main
import (
"fmt"
"io/ioutil"
"time"
)
type Coords struct {
x int
y int
}
func main() {
fmt.Println("Day 3")
start := time.Now()
dat, err := ioutil.ReadFile("day3.txt")
if err != nil {
panic(err)
}
position := Coords{x: 0, y: 0}
visited := make(map[Coords]int)
visited[position] = 1
for _, value := range dat {
solve(visited, &position, value)
}
elapsed := time.Since(start)
fmt.Printf("Part 1: %v %v \n", len(visited), elapsed)
start = time.Now()
position = Coords{x: 0, y: 0}
visited = make(map[Coords]int)
visited[position] = 1
for i := 0; i < len(dat); i = i + 2 {
solve(visited, &position, dat[i])
}
position.x = 0
position.y = 0
for i := 1; i < len(dat); i = i + 2 {
solve(visited, &position, dat[i])
}
fmt.Printf("Part 2: %v %v", len(visited), elapsed)
}
func solve(visited map[Coords]int, position *Coords, value byte) {
if value == []byte("<")[0] {
position.x--
visited[*position]++
} else if value == []byte(">")[0] {
position.x++
visited[*position]++
} else if value == []byte("^")[0] {
position.y++
visited[*position]++
} else if value == []byte("v")[0] {
position.y--
visited[*position]++
}
}