feat: I think I'm getting closer

cmd/11/main.go

@@ -5,6 +5,7 @@ import (
 	"strings"
 
 	"github.com/StevanFreeborn/advent-of-code-2025/internal/file"
+	"github.com/StevanFreeborn/advent-of-code-2025/internal/queue"
 	"github.com/StevanFreeborn/advent-of-code-2025/internal/stack"
 )
 
@@ -47,8 +48,9 @@ func SolvePartOne(filePath string) int {
 }
 
 type node struct {
-	value               string
-	numberOfParentPaths int
+	value   string
+	fftSeen bool
+	dacSeen bool
 }
 
 func SolvePartTwo(filePath string) int {
@@ -65,21 +67,20 @@ func SolvePartTwo(filePath string) int {
 	stack.Push(node{
 		value: SVR_NODE,
 	})
-	visisted := map[node]int{}
 	pathCount := 0
 
 	for stack.IsEmpty() == false {
 		current, _ := stack.Pop()
 
-		_, ok := visisted[current]
-
-		if ok {
-			visisted[current]++
-		} else {
-			visisted[current] = 1
+		if current.value == FFT_NODE {
+			current.fftSeen = true
 		}
 
-		if current.value == OUT_NODE {
+		if current.value == DAC_NODE {
+			current.dacSeen = true
+		}
+
+		if current.value == OUT_NODE && current.dacSeen && current.fftSeen {
 			pathCount++
 			continue
 		}
@@ -88,12 +89,84 @@ func SolvePartTwo(filePath string) int {
 
 		for _, n := range neighbors {
 			stack.Push(node{
-				value: n,
+				value:   n,
+				fftSeen: current.fftSeen,
+				dacSeen: current.dacSeen,
 			})
 		}
 	}
 
-	fmt.Println(visisted)
-
 	return pathCount
 }
+
+func SolvePartTwoAgain(filePath string) int {
+	adjacencyList := map[string][]string{}
+	inDegrees := map[string]int{}
+	allNodes := map[string]bool{}
+
+	for line := range file.ReadLines(filePath) {
+		parts := strings.Split(line, ": ")
+		from := parts[0]
+		toList := strings.Split(parts[1], " ")
+
+		allNodes[from] = true
+
+		_, existingInDegrees := inDegrees[from]
+
+		if existingInDegrees == false {
+			inDegrees[from] = 0
+		}
+
+		for _, to := range toList {
+			allNodes[to] = true
+			adjacencyList[from] = append(adjacencyList[from], to)
+			inDegrees[to]++
+		}
+	}
+
+	queue := queue.New[string]()
+
+	for node := range allNodes {
+		if inDegrees[node] == 0 {
+			queue.Enqueue(node)
+		}
+	}
+
+	processOrder := []string{}
+
+	for queue.IsEmpty() == false {
+		current, _ := queue.Dequeue()
+		processOrder = append(processOrder, current)
+
+		for _, neighbor := range adjacencyList[current] {
+			inDegrees[neighbor]--
+
+			if inDegrees[neighbor] == 0 {
+				queue.Enqueue(neighbor)
+			}
+		}
+	}
+
+	pathsCount := map[string]int{}
+	pathsCount[SVR_NODE] = 1
+
+	for _, item := range processOrder {
+		if pathsCount[item] == 0 {
+			continue
+		}
+
+		for _, n := range adjacencyList[item] {
+			pathsCount[n] += pathsCount[item]
+		}
+	}
+
+	// TODO: Could I process the graph
+	// in smaller pieces and then multiply
+	// those path to figure out what the
+	// total number of paths are.
+	fmt.Println(pathsCount[OUT_NODE])
+	fmt.Println(pathsCount[DAC_NODE])
+	fmt.Println(pathsCount[FFT_NODE])
+
+	return 0
+}

cmd/11/main_test.go

@@ -48,3 +48,23 @@ func TestSolvePartTwoWithInput(t *testing.T) {
 		t.Errorf("SolvePartTwo(INPUT.txt) = %d; want %d", result, expected)
 	}
 }
+
+func TestSolvePartTwoAgainWithExampleInput(t *testing.T) {
+	expected := 2
+
+	result := solution.SolvePartTwoAgain("EXAMPLE_TWO.txt")
+
+	if result != expected {
+		t.Errorf("SolvePartTwoAgain(EXAMPLE_TWO.txt) = %d; want %d", result, expected)
+	}
+}
+
+func TestSolvePartTwoAgainWithInput(t *testing.T) {
+	expected := -1
+
+	result := solution.SolvePartTwoAgain("INPUT.txt")
+
+	if result != expected {
+		t.Errorf("SolvePartTwoAgain(INPUT.txt) = %d; want %d", result, expected)
+	}
+}