Solve seven

2025/seven/seven.go

@@ -2,10 +2,8 @@ package main
 
 import (
 	"bufio"
-	"errors"
 	"fmt"
 	"os"
-	"strconv"
 	"strings"
 )
 
@@ -15,18 +13,27 @@ func check(err error) {
 	}
 }
 
-type beam int
 type beams struct {
-	b map[beam]struct{}
+	list map[int]int
 }
 
-func (b *beams) add(pos beam) {
-	b.b[pos] = {}
+func newBeams() beams {
+	var b beams
+	b.list = make(map[int]int)
+	return b
+}
+
+func (b *beams) add(pos int) {
+	b.list[pos]++
+}
+
+func (b *beams) del(pos int) {
+	delete(b.list, pos)
 }
 
 func main() {
 
-	file, err := os.Open("five.txt")
+	file, err := os.Open("seven.txt")
 	check(err)
 	defer file.Close()
 
@@ -36,35 +43,24 @@ func main() {
 	text := scanner.Text()
 
 	start := strings.IndexRune(text, 'S')
-	beams.add(beam(start))
+	beamSet := make(map[int]int)
+	beamSet[start] = 1
 
 	for scanner.Scan() {
-	}
-	db, err := parse(scanner)
-
-	check(err)
-
-	nRaw := len(db.ranges)
-
-	for {
-		before, after := db.collapse()
-
-		fmt.Printf("Collapsed %d to %d ranges\n", before, after)
-
-		if before == after {
-			break
+		text := scanner.Text()
+		for beam, nways := range beamSet {
+			if text[beam] == '^' {
+				beamSet[beam-1] += nways
+				beamSet[beam+1] += nways
+				delete(beamSet, beam)
+			}
 		}
 	}
 
-	potentialNFresh := 0
-	for _, r := range db.ranges {
-		potentialNFresh += r.nInRange()
+	timelines := 0
+	for _, nways := range beamSet {
+		timelines += nways
 	}
 
-	fmt.Printf(
-		"N raw %d and consolidated %d. %d potential fresh ingredients.\n",
-		nRaw,
-		len(db.ranges),
-		potentialNFresh,
-	)
+	fmt.Printf("N splits: %d\n", timelines)
 }