89 lines
1.2 KiB
Go
89 lines
1.2 KiB
Go
package main
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import (
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"bufio"
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"fmt"
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"math"
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"os"
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"strings"
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)
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// cat input | go run 11.go
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func main() {
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scanner := bufio.NewScanner(os.Stdin)
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for scanner.Scan() {
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s := strings.Split(scanner.Text(), ",")
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fmt.Println(CalcDistance(s))
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}
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}
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func CalcDistance(s []string) []int {
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x := 0
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ne := 0
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max := 0
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// I had a crack at this with an approximation of a cube based coordinate system
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// but the maths is hard and I suck. In the end I sought inspiration from
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// https://www.redblobgames.com/grids/hexagons/ - and am now using axial coordinates
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for dir := range s {
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switch s[dir] {
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case "n":
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ne++
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case "s":
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ne--
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case "se":
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x++
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case "sw":
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x--
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ne--
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case "ne":
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x++
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ne++
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case "nw":
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x--
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}
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// Inefficient, but I'm running out of lunchtime.
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cd := getDistance(x, ne)
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if cd > max {
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max = cd
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}
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}
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cd := getDistance(x, ne)
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return []int{cd, max}
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}
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func getDistance(x int, ne int) int {
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steps := 0
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for !(ne == 0 || x == 0) {
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switch {
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case ne > 0 && x > 0:
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steps++
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ne--
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x--
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case ne < 0 && x > 0:
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steps++
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ne++
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case ne > 0 && x < 0:
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steps++
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x++
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case ne < 0 && x < 0:
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steps++
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ne++
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x++
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}
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}
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return (steps + int(math.Abs(float64(x))) + int(math.Abs(float64(ne))))
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}
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