From d94663d31037a91afe5d32784919d859d94d812e Mon Sep 17 00:00:00 2001
From: Ben Charlton <ben@spod.cx>
Date: Tue, 12 Dec 2017 21:41:07 +0000
Subject: [PATCH] day 12

---
 12/12.go      | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++
 12/12_test.go | 40 ++++++++++++++++++++++++
 2 files changed, 126 insertions(+)
 create mode 100644 12/12.go
 create mode 100644 12/12_test.go

diff --git a/12/12.go b/12/12.go
new file mode 100644
index 0000000..f6c93c5
--- /dev/null
+++ b/12/12.go
@@ -0,0 +1,86 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"strings"
+	"strconv"
+)
+
+// cat input | go run 12.go
+
+type pipedata struct {
+	pipe int
+	linkedTo []int
+}
+
+func main() {
+
+	scanner := bufio.NewScanner(os.Stdin)
+
+	var pd = []pipedata{}
+
+	for scanner.Scan() {
+
+		s := strings.Split(scanner.Text(), " <-> ")
+		pipe,_ := strconv.Atoi(s[0])
+
+		var linkedTo = []int{}
+		l := strings.Split(s[1], ", ")
+		for t := range l {
+			i, _ := strconv.Atoi(l[t])
+			linkedTo = append(linkedTo, i)
+		}
+
+		pd = append(pd, pipedata{pipe, linkedTo})
+	}
+
+	cp := CountPipes(pd)
+	seenGroups := make(map[int]int)
+	groups,_ := CountGroups(seenGroups, pd)
+
+	fmt.Println(cp,groups)
+}
+
+
+func CountPipes(pipedata []pipedata) int {
+	seen := make(map[int]int)
+	seen = getChildren(seen, pipedata, 0)
+	fmt.Println(seen)
+	
+	count := 0
+	for range seen {
+		count++
+	}
+
+	return count
+
+}
+
+func CountGroups(seen map[int]int, pipedata []pipedata) (int,map[int]int) {
+	count := 0
+	for i := range pipedata {
+		if seen[i] > 0 {
+			continue
+		} else {
+			seen = getChildren(seen, pipedata, i)
+			count++ 
+		}
+	}
+	return count,seen
+}
+
+func getChildren(seen map[int]int, pipedata []pipedata, pipe int) map[int]int {
+
+	p := pipedata[pipe]
+	for l := range p.linkedTo {
+		child := p.linkedTo[l]
+		if (seen[child] == 0) {
+			seen[child]++
+			seen = getChildren(seen, pipedata, child)
+		} 
+	}
+
+	return seen
+}
\ No newline at end of file
diff --git a/12/12_test.go b/12/12_test.go
new file mode 100644
index 0000000..3ae766c
--- /dev/null
+++ b/12/12_test.go
@@ -0,0 +1,40 @@
+package main
+
+import (
+	"testing"
+)
+
+  
+  var tests = []pipedata{
+		{0, []int{2}},
+		{1, []int{1}},
+		{2, []int{0, 3, 4}},
+		{3, []int{2, 4}},
+		{4, []int{2, 3, 6}},
+		{5, []int{6}},
+		{6, []int{4, 5}},
+  }
+
+func TestCountPipes(t *testing.T) {
+		v := CountPipes(tests)
+		if v != 6 {
+		  t.Error(
+			"For", tests,
+			"expected 6",
+			"got", v,
+		  )
+	  }
+}
+
+
+func TestCountGroups(t *testing.T) {
+	seen := make(map[int]int)
+	v,_ := CountGroups(seen, tests)
+  if v != 2 {
+    t.Error(
+    "For", tests,
+    "expected 2",
+    "got", v,
+    )
+  }
+}
\ No newline at end of file