From e78eb5781e458a55e26c3a3f7ef6c9a9e6af315f Mon Sep 17 00:00:00 2001
From: Brian Buller <brbuller@gmail.com>
Date: Tue, 26 Dec 2017 08:16:20 -0600
Subject: [PATCH] Switching computers

---
 2017/day24/day24.go  | 203 +++++++++++++++++++++++++++++++++++++++++++
 2017/day24/input     |  57 ++++++++++++
 2017/day24/testinput |   8 ++
 3 files changed, 268 insertions(+)
 create mode 100644 2017/day24/day24.go
 create mode 100644 2017/day24/input
 create mode 100644 2017/day24/testinput

diff --git a/2017/day24/day24.go b/2017/day24/day24.go
new file mode 100644
index 0000000..95e0b58
--- /dev/null
+++ b/2017/day24/day24.go
@@ -0,0 +1,203 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"os"
+	"strconv"
+	"strings"
+)
+
+var comps []Component
+
+// Greater than 907
+func main() {
+	inp := StdinToStrings()
+	for i := range inp {
+		comps = append(comps, NewComponent(inp[i]))
+	}
+
+	// Need to build chains of all permutations
+	var perms []Bridge
+	for i := range comps {
+		if comps[i].Has(0) {
+			perms = append(perms, Bridge([]Component{comps[i]}))
+		}
+	}
+
+	changed := true
+	for changed {
+		perms, changed = GetNextPerms(perms)
+	}
+
+	var highB Bridge
+	highest := 0
+	for _, b := range perms {
+		if b.Value() > highest {
+			highB = b
+			highest = b.Value()
+		}
+	}
+	fmt.Println(highB)
+	/*
+		for _, b := range perms {
+			tst := GetAllThatFit(b)
+			for i := range tst {
+
+			}
+
+			for tst != nil {
+				b = b.Add(*tst)
+				tst = GetNextBest(b)
+			}
+			fmt.Println(b)
+		}
+	*/
+}
+
+func GetNextPerms(perms []Bridge) ([]Bridge, bool) {
+	var ret []Bridge
+	var changed bool
+	for i := range perms {
+		if !perms[i].IsDone() {
+			allComps := GetAllThatFit(perms[i])
+			if len(allComps) == 0 {
+				ret = append(ret, perms[i].Add(NewComponent("0/0")))
+			}
+			for j := range allComps {
+				ret = append(ret, perms[i].Add(allComps[j]))
+				changed = true
+			}
+		}
+	}
+	return ret, changed
+}
+
+func GetAllThatFit(b Bridge) []Component {
+	var ret []Component
+	port := b.Needs()
+	for i := range comps {
+		if comps[i].Has(port) && !b.Has(comps[i]) {
+			ret = append(ret, comps[i])
+		}
+	}
+	return ret
+}
+
+func GetNextBest(b Bridge) *Component {
+	var best *Component
+	port := b.Needs()
+	for i := range comps {
+		if comps[i].Has(port) && !b.Has(comps[i]) {
+			if best == nil || comps[i].Value() > best.Value() {
+				best = &comps[i]
+			}
+		}
+	}
+	return best
+}
+
+type Bridge []Component
+
+func (b Bridge) IsDone() bool {
+	t := []Component(b)
+	c := t[len(t)-1]
+	return c.Value() == 0
+}
+
+func (b Bridge) Value() int {
+	var ret int
+	for _, v := range []Component(b) {
+		ret += v.Value()
+	}
+	return ret
+}
+
+func (b Bridge) Has(c Component) bool {
+	for _, v := range []Component(b) {
+		if v.Name == c.Name {
+			return true
+		}
+	}
+	return false
+}
+
+func (b Bridge) Add(c Component) Bridge {
+	b = Bridge(append([]Component(b), c))
+	return b
+}
+
+func (b Bridge) Needs() int {
+	t := []Component(b)
+	c := t[len(t)-1]
+	if len(t) == 1 {
+		return c.Other(0)
+	}
+	c1 := t[len(t)-2]
+
+	// Find the side of c that doesn't connect with c1
+	if c.Has(c1.Side1) {
+		return c.Other(c1.Side1)
+	}
+	return c.Other(c1.Side2)
+}
+
+func (b Bridge) String() string {
+	ret := "[ "
+	for _, v := range []Component(b) {
+		ret += v.Name + " "
+	}
+	return fmt.Sprint(ret+"] ", b.Value())
+}
+
+type Component struct {
+	Name         string
+	Side1, Side2 int
+}
+
+func NewComponent(in string) Component {
+	c := Component{}
+	c.Name = in
+	pts := strings.Split(in, "/")
+	c.Side1 = Atoi(pts[0])
+	c.Side2 = Atoi(pts[1])
+	return c
+}
+
+func (c *Component) Equals(t Component) bool {
+	return c.Side1 == t.Side1 && c.Side2 == t.Side2
+}
+
+func (c *Component) Value() int {
+	return c.Side1 + c.Side2
+}
+
+func (c *Component) Has(v int) bool {
+	return c.Side1 == v || c.Side2 == v
+}
+
+func (c *Component) Other(v int) int {
+	if c.Side1 == v {
+		return c.Side2
+	}
+	return c.Side1
+}
+
+func Atoi(i string) int {
+	var ret int
+	var err error
+	if ret, err = strconv.Atoi(i); err != nil {
+		log.Fatal("Invalid Atoi")
+	}
+	return ret
+}
+
+func StdinToStrings() []string {
+	var input []string
+	scanner := bufio.NewScanner(os.Stdin)
+	for scanner.Scan() {
+		input = append(input, scanner.Text())
+	}
+	return input
+}
diff --git a/2017/day24/input b/2017/day24/input
new file mode 100644
index 0000000..383dcb0
--- /dev/null
+++ b/2017/day24/input
@@ -0,0 +1,57 @@
+25/13
+4/43
+42/42
+39/40
+17/18
+30/7
+12/12
+32/28
+9/28
+1/1
+16/7
+47/43
+34/16
+39/36
+6/4
+3/2
+10/49
+46/50
+18/25
+2/23
+3/21
+5/24
+46/26
+50/19
+26/41
+1/50
+47/41
+39/50
+12/14
+11/19
+28/2
+38/47
+5/5
+38/34
+39/39
+17/34
+42/16
+32/23
+13/21
+28/6
+6/20
+1/30
+44/21
+11/28
+14/17
+33/33
+17/43
+31/13
+11/21
+31/39
+0/9
+13/50
+10/14
+16/10
+3/24
+7/0
+50/50
diff --git a/2017/day24/testinput b/2017/day24/testinput
new file mode 100644
index 0000000..f2c8f2a
--- /dev/null
+++ b/2017/day24/testinput
@@ -0,0 +1,8 @@
+0/2
+2/2
+2/3
+3/4
+3/5
+0/1
+10/1
+9/10