2021 Day 21 Complete

2021/day19/main.go

@@ -1,7 +1,112 @@
 package main
 
-import "fmt"
+import (
+	"errors"
+	"fmt"
+	"os"
+	"strings"
+
+	h "git.bullercodeworks.com/brian/adventofcode/helpers"
+)
 
 func main() {
-	fmt.Println("vim-go")
+	inp := h.StdinToStringSlice()
+	scanners := parseScanners(inp)
+	foundBeacons := scanners[0].beacons
+	foundScannerPositions := []beacon{{0, 0, 0}}
+
+	remaining := scanners[1:]
+	for len(remaining) > 0 {
+		var wrk scanner
+		wrk, remaining = remaining[0], remaining[1:]
+		s := NewScanner(foundBeacons).getScannerFromOverlap(wrk)
+		if s == nil {
+			remaining = append(remaining, s)
+		} else {
+			foundBeacons = append(foundBeacons, s.beacons...)
+			//foundScannerPositions = append(foundScannerPositions,
+		}
+	}
+}
+
+func parseScanners(inp []string) []scanner {
+	var scanners []scanner
+	for i := range inp {
+		if strings.HasPrefix(inp[i], "---") {
+			// Find the next empty line
+			end := i
+			for ; end < len(inp); end++ {
+				if inp[end] == "" {
+					break
+				}
+			}
+			// a new scanner
+			wrk, err := NewScannerFromInput(inp[i:end])
+			if err == nil {
+				scanners = append(scanners, wrk)
+			} else {
+				fmt.Println("Error parsing scanners")
+				os.Exit(1)
+			}
+		}
+	}
+	return scanners
+}
+
+type scanner struct {
+	number  int
+	region  map[h.Coordinate]bool
+	beacons []beacon
+}
+
+func NewScanner(b []beacon) scanner {
+	return scanner{beacons: b}
+}
+
+func NewScannerFromInput(inp []string) (scanner, error) {
+	s := scanner{}
+	r := strings.NewReader(inp[0])
+	_, err := fmt.Fscanf(r, "--- scanner %d ---", &s.number)
+	if err != nil {
+		return s, errors.New("No Scanner ID")
+	}
+	for _, v := range inp[1:] {
+		r = strings.NewReader(v)
+		b := beacon{}
+		_, err := fmt.Fscanf(r, "%d,%d,%d", &b.x, &b.y, &b.z)
+		if err == nil {
+			s.beacons = append(s.beacons, b)
+		}
+	}
+	return s, nil
+}
+
+func (s scanner) allRotations() [][]beacon {
+	var beacons [][]beacon
+	for i := range s.beacons {
+		beacons = append(beacons, s.beacons[i].allRotations())
+	}
+	return beacons
+}
+
+func (s scanner) String() string {
+	return fmt.Sprintf("-- Scanner %d (%d beacons)---", s.number, len(s.beacons))
+}
+
+type beacon struct {
+	x, y, z int
+}
+
+func (b beacon) allRotations() []beacon {
+	return []beacon{
+		{b.x, b.y, b.z}, {b.x, -b.z, b.y}, {b.x, -b.y, -b.z}, {b.x, b.z, -b.y}, {-b.x, -b.y, b.z},
+		{-b.x, -b.z, -b.y}, {-b.x, b.y, -b.z}, {-b.x, b.z, b.y}, {-b.z, b.x, -b.y}, {b.y, b.x, -b.z},
+		{b.z, b.x, b.y}, {-b.y, b.x, b.z}, {b.z, -b.x, -b.y}, {b.y, -b.x, b.z}, {-b.z, -b.x, b.y},
+		{-b.y, -b.x, -b.z}, {-b.y, -b.z, b.x}, {b.z, -b.y, b.x}, {b.y, b.z, b.x}, {-b.z, b.y, b.x},
+		{b.z, b.y, -b.x}, {-b.y, b.z, -b.x}, {-b.z, -b.y, -b.x}, {b.y, -b.z, -b.x},
+	}
+}
+
+func (b beacon) String() string {
+	return fmt.Sprintf("{%d,%d,%d}", b.x, b.y, b.z)
 }