From 302e593f0f7b29f56a057652ec0fc3e17d2d1997 Mon Sep 17 00:00:00 2001
From: Ben Charlton <ben@spod.cx>
Date: Mon, 11 Dec 2017 13:44:13 +0000
Subject: [PATCH] day 11
---
11/11.go | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 84 insertions(+)
create mode 100644 11/11.go
diff --git a/11/11.go b/11/11.go
new file mode 100644
index 0000000..8bcec4d
--- /dev/null
+++ b/11/11.go
@@ -0,0 +1,84 @@
+package main
+
+import (
+ "bufio"
+ "fmt"
+ "math"
+ "os"
+ "strings"
+)
+
+// cat input | go run 11.go
+
+func main() {
+
+ scanner := bufio.NewScanner(os.Stdin)
+
+ for scanner.Scan() {
+ s := strings.Split(scanner.Text(), ",")
+
+ x := 0
+ ne := 0
+ max := 0
+
+ // I had a crack at this with an approximation of a cube based coordinate system
+ // but the maths is hard and I suck. In the end I sought inspiration from
+ // https://www.redblobgames.com/grids/hexagons/ - and am now using axial coordinates
+ for dir := range s {
+ switch s[dir] {
+ case "n":
+ ne++
+ case "s":
+ ne--
+ case "se":
+ x++
+ case "sw":
+ x--
+ ne--
+ case "ne":
+ x++
+ ne++
+ case "nw":
+ x--
+ }
+
+ // Inefficient, but I'm running out of lunchtime.
+ cd := getDistance(x, ne)
+ if cd > max {
+ max = cd
+ }
+
+ }
+
+ fmt.Println(getDistance(x, ne), max)
+
+ }
+}
+
+func getDistance(x int, ne int) int {
+
+ steps := 0
+ for !(ne == 0 || x == 0) {
+
+ switch {
+ case ne > 0 && x > 0:
+ steps++
+ ne--
+ x--
+
+ case ne < 0 && x > 0:
+ steps++
+ ne++
+ case ne > 0 && x < 0:
+ steps++
+ x++
+
+ case ne < 0 && x < 0:
+ steps++
+ ne++
+ x++
+
+ }
+ }
+ return (steps + int(math.Abs(float64(x))) + int(math.Abs(float64(ne))))
+}