2018 Day 20 Done

* Also some cleanup on helpers.go

2018/day20/day20.go

@@ -0,0 +1,157 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+)
+
+const (
+	CLEAR_SCREEN = "\033[H\033[2J"
+
+	MAX_INT = int(^uint(0) >> 1)
+	MIN_INT = -MAX_INT - 1
+)
+
+var input []byte
+var currRoom *Room
+var facility *Facility
+var pathStack []Room
+
+func main() {
+	input = stdinToByteSlice()
+	input = input[1 : len(input)-1] // Trim ^...$
+	part1()
+	part2()
+}
+
+func part1() {
+	facility = NewFacility()
+	currRoom = &Room{0, 0, 0}
+	for _, v := range input {
+		switch v {
+		case 'N':
+			facility.move(0, -1)
+		case 'E':
+			facility.move(1, 0)
+		case 'S':
+			facility.move(0, 1)
+		case 'W':
+			facility.move(-1, 0)
+		case '(':
+			pathStack = append(pathStack, *currRoom)
+		case ')':
+			currRoom, pathStack = &pathStack[len(pathStack)-1], pathStack[:len(pathStack)-1]
+		case '|':
+			currRoom = &pathStack[len(pathStack)-1]
+		}
+	}
+	var longest int
+	for _, v := range facility.rooms {
+		if v.dist > longest {
+			longest = v.dist
+		}
+	}
+	fmt.Println("= Part 1 =")
+	fmt.Println(longest)
+}
+
+func part2() {
+	var kilo int
+	for _, v := range facility.rooms {
+		if v.dist >= 1000 {
+			kilo++
+		}
+	}
+	fmt.Println("= Part 2 =")
+	fmt.Println(kilo)
+}
+
+type Facility struct {
+	minX, maxX int
+	minY, maxY int
+	rooms      map[string]*Room
+}
+
+func NewFacility() *Facility {
+	f := Facility{
+		minX:  MAX_INT,
+		maxX:  MIN_INT,
+		minY:  MAX_INT,
+		maxY:  MIN_INT,
+		rooms: make(map[string]*Room),
+	}
+	return &f
+}
+
+func (f *Facility) key(x, y int) string {
+	return fmt.Sprintf("%d,%d", x, y)
+}
+
+func (f *Facility) move(xd, yd int) {
+	n := f.getRoom(currRoom.x+xd, currRoom.y+yd)
+	n.dist = min(n.dist, currRoom.dist+1)
+	currRoom = n
+	f.setRoom(n)
+}
+
+func (f *Facility) getRoom(x, y int) *Room {
+	if v, ok := f.rooms[f.key(x, y)]; ok {
+		return v
+	}
+	return &Room{x, y, MAX_INT}
+}
+
+func (f *Facility) setRoom(r *Room) {
+	f.minX = min(f.minX, r.x)
+	f.maxX = max(f.maxX, r.x)
+	f.minY = min(f.minY, r.y)
+	f.maxY = max(f.maxY, r.y)
+	f.rooms[r.key()] = r
+}
+
+func (f *Facility) string() string {
+	var ret string
+	for y := f.minY; y < f.maxY; y++ {
+		for x := f.minX; x < f.maxX; x++ {
+			if r, ok := f.rooms[f.key(x, y)]; !ok {
+				ret += " " + r.key() + " "
+			}
+		}
+		ret += "\n"
+	}
+	return ret
+}
+
+type Room struct {
+	x, y int
+	dist int
+}
+
+func (r *Room) key() string {
+	return fmt.Sprintf("%d,%d", r.x, r.y)
+}
+
+func min(i, j int) int {
+	if j < i {
+		return j
+	}
+	return i
+}
+
+func max(i, j int) int {
+	if j > i {
+		return j
+	}
+	return i
+}
+
+func stdinToByteSlice() []byte {
+	var ret []byte
+	scanner := bufio.NewScanner(os.Stdin)
+	for scanner.Scan() {
+		data := scanner.Bytes()
+		ret = append(input, data...)
+	}
+	return ret
+}

2018/day20/testinput

@@ -0,0 +1 @@
+^ESSWWN(E|NNENN(EESS(WNSE|)SSS|WWWSSSSE(SW|NNNE)))$

2018/day20/testinput2

@@ -0,0 +1 @@
+^WSSEESWWWNW(S|NENNEEEENN(ESSSSW(NWSW|SSEN)|WSWWN(E|WWS(E|SS))))$

helpers.go

@@ -10,6 +10,23 @@ import (
 	"strings"
 )
 
+// Some handy Constants
+const (
+	BORDER_NS = "\u2502"
+	BORDER_WE = "\u2500"
+
+	BORDER_NW = "\u250C"
+	BORDER_NE = "\u2510"
+	BORDER_SW = "\u2514"
+	BORDER_SE = "\u2518"
+
+	FILL_CHAR    = "\u2588"
+	CLEAR_SCREEN = "\033[H\033[2J"
+
+	MAX_INT = int(^uint(0) >> 1)
+	MIN_INT = -MAX_INT - 1
+)
+
 func ArgIsSet(a string) bool {
 	for i := range os.Args {
 		if os.Args[i] == a || strings.HasPrefix(os.Args[i], a+"=") {
@@ -124,17 +141,3 @@ func stringPermHelper(str string, i int) []string {
 	}
 	return ret
 }
-
-// Some character code stuff for prettier output
-const (
-	BorderNS = "\u2502"
-	BorderWE = "\u2500"
-
-	BorderNW = "\u250C"
-	BorderNE = "\u2510"
-	BorderSW = "\u2514"
-	BorderSE = "\u2518"
-
-	FillChar    = "\u2588"
-	ClearScreen = "\033[H\033[2J"
-)