day 07 part 1 works, 2 too slow

07/main.go

@@ -0,0 +1,110 @@
+package main
+
+import (
+	"fmt"
+
+	"git.z1glr.de/advent-of-code-2025/pkg/aoc"
+)
+
+type Schematic struct {
+	rows   [][]byte
+	splits int
+}
+
+func (s *Schematic) CalculateRow(i int) {
+	if i == len(s.rows)-1 {
+		return
+	}
+
+	for ii, char := range s.rows[i] {
+		switch char {
+		case byte('S'), byte('|'):
+			s.processPosition(i+1, ii)
+		}
+	}
+
+	s.CalculateRow(i + 1)
+}
+
+func (s *Schematic) processPosition(row, index int) {
+	if s.rows[row][index] == byte('.') {
+		s.rows[row][index] = byte('|')
+	} else if s.rows[row][index] == byte('^') {
+		s.splits++
+
+		s.rows[row][index-1] = byte('|')
+		s.rows[row][index+1] = byte('|')
+	}
+}
+
+func (s *Schematic) Clone() *Schematic {
+	returnSchematic := Schematic{
+		rows:   make([][]byte, len(s.rows)),
+		splits: s.splits,
+	}
+
+	for ii, rr := range s.rows {
+		returnSchematic.rows[ii] = make([]byte, len(rr))
+		copy(returnSchematic.rows[ii], s.rows[ii])
+	}
+
+	return &returnSchematic
+}
+
+func (s Schematic) CalculateQuantumRow(i int, pathCount *int) {
+	if i == len(s.rows)-1 {
+		return
+	}
+
+	for ii, char := range s.rows[i] {
+		switch char {
+		case byte('S'), byte('|'):
+			if s.rows[i+1][ii] == byte('^') {
+				(*pathCount)++
+
+				parallelPath := s.Clone()
+
+				s.rows[i+1][ii-1] = byte('|')
+				parallelPath.rows[i+1][ii+1] = byte('|')
+
+				parallelPath.CalculateQuantumRow(i+1, pathCount)
+			} else {
+				s.rows[i+1][ii] = byte('|')
+			}
+			s.CalculateQuantumRow(i+1, pathCount)
+			return
+		}
+	}
+	s.CalculateQuantumRow(i+1, pathCount)
+}
+
+func do(test bool) (int, int) {
+	rows := aoc.ReadFileRows(test)
+
+	schematic := Schematic{
+		rows: make([][]byte, len(rows)),
+	}
+
+	for ii, rr := range rows {
+		schematic.rows[ii] = []byte(rr)
+	}
+
+	quantumSchematic := schematic.Clone()
+
+	schematic.CalculateRow(0)
+
+	timelines := 1
+
+	quantumSchematic.CalculateQuantumRow(0, &timelines)
+
+	fmt.Println(schematic.splits)
+	fmt.Println(timelines)
+
+	return schematic.splits, timelines
+}
+
+func main() {
+	if r1, r2 := do(true); r1 == 21 && r2 == 40 {
+		do(false)
+	}
+}