make use of graph factory function.

move isLoop logic into guard clause.

day-06/internal/one/graph.go

@@ -7,8 +7,8 @@ import (
 )
 
 type graph struct {
-	data       []string
 	startPoint point
+	data       []string
 }
 
 func newGraph() *graph {

day-06/internal/two/graph.go

@@ -7,12 +7,12 @@ import (
 )
 
 type graph struct {
-	data       []string
 	startPoint point
+	data       []string
 }
 
-func newGraph() *graph {
-	return &graph{}
+func newGraph(startPoint point, data []string) *graph {
+	return &graph{startPoint: startPoint, data: data}
 }
 
 func (g *graph) String() string {

day-06/internal/two/solve.go

@@ -24,9 +24,7 @@ func Solve(buf []byte) (int, error) {
 			continue
 		}
 
-		g := newGraph()
-		g.startPoint = graph.startPoint
-		g.data = slices.Clone(graph.data)
+		g := newGraph(graph.startPoint, slices.Clone(graph.data))
 		g.data[loc.Y] = replaceAtIndex(g.data[loc.Y], 'O', loc.X)
 
 		p := g.startPoint
@@ -43,13 +41,13 @@ func Solve(buf []byte) (int, error) {
 				}
 
 				_, ok := visited[p]
-				if !ok {
-					visited[p] = struct{}{}
-				} else {
+				if ok {
 					log.Tracef("loop: \n%s\n", g.trace(visited))
 					isLoop <- true
 					return
 				}
+
+				visited[p] = struct{}{}
 			}
 			isLoop <- false
 		}()

day-06/internal/two/util.go

@@ -7,7 +7,7 @@ import (
 )
 
 func parseLines(r io.Reader) (*graph, error) {
-	graph := newGraph()
+	graph := &graph{}
 
 	count := 0
 	scanner := bufio.NewScanner(r)