adventofcode/day01/main.go

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1.7 KiB
Go
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2016-12-01 13:46:32 +00:00
package main
import (
"fmt"
"io"
"log"
"math"
"strconv"
"strings"
)
const (
north = iota
east
south
west
)
type pos struct {
dir int
x int
y int
}
func (s *pos) TurnLeft() {
s.dir++
if s.dir > west {
s.dir = north
}
}
func (s *pos) TurnRight() {
s.dir--
if s.dir < north {
s.dir = west
}
}
func (s *pos) CoordsToString() string {
return strconv.Itoa(s.x) + "-" + strconv.Itoa(s.y)
}
func (s *pos) DistanceTravelled() int {
return int(math.Abs(float64(s.y)) + math.Abs(float64(s.x)))
}
func (s *pos) Walk(dist int) {
switch s.dir {
case north:
s.y += dist
case east:
s.x += dist
case south:
s.y -= dist
case west:
s.x -= dist
}
}
func main() {
var input string
var readInp string
travelLog := make(map[string]int)
firstRepeat := false
currPos := pos{dir: north, x: 0, y: 0}
travelLog[currPos.CoordsToString()]++
for {
_, err := fmt.Scan(&readInp)
if err != nil {
if err != io.EOF {
log.Fatal(err)
}
break
}
input += readInp
}
for _, k := range strings.Split(input, ",") {
k = strings.Trim(k, " ")
if k[0] == 'R' {
currPos.TurnRight()
} else {
currPos.TurnLeft()
}
tDist := atoi(k[1:])
for mvI := 0; mvI < tDist; mvI++ {
currPos.Walk(1)
if !firstRepeat && travelLog[currPos.CoordsToString()] > 0 {
fmt.Println(" First Repeated Position: " + currPos.CoordsToString())
fmt.Println(" Distance: ", currPos.DistanceTravelled())
firstRepeat = true
}
travelLog[currPos.CoordsToString()]++
}
}
fmt.Println("End Position: ", currPos.x, ",", currPos.y)
fmt.Println(" Distance: ", currPos.DistanceTravelled())
}
func atoi(inp string) int {
var err error
var i int
if i, err = strconv.Atoi(inp); err != nil {
log.Fatal(err.Error())
}
return i
}