Day 13 solution

thirteen/main.go

@@ -0,0 +1,26 @@
+package thirteen
+
+import "fmt"
+
+type Thirteen struct {
+	manual manual
+}
+
+func Init(filepath string) *Thirteen {
+	thirteen := &Thirteen{
+		manual: manual{},
+	}
+
+	thirteen.manual.load(filepath)
+	return thirteen
+}
+
+func (d *Thirteen) Answer() string {
+	_, dots := foldGrid(d.manual.folds[0], d.manual.dots)
+	return fmt.Sprintf("There are %d dots after 1 fold", dots)
+}
+
+func (d *Thirteen) FollowUp() string {
+	d.manual.fold()
+	return "This is the activation code"
+}