edge case

main.go

@@ -16,11 +16,13 @@ func MaxValue(capacity uint, books []Book) uint {
 	}
 
 	book := books[0]
-	return Max(
-		book.Value+MaxValue(capacity-book.Weight, books[1:]),
-		MaxValue(capacity, books[1:]),
-	)
+	withBook := book.Value + MaxValue(capacity-book.Weight, books[1:])
+	withoutBook := MaxValue(capacity, books[1:])
+	if book.Weight > capacity {
+		return withoutBook
+	}
 
+	return Max(withBook, withoutBook)
 }
 
 func main() {

main_test.go

@@ -35,3 +35,11 @@ func TestPrefersMultiple(t *testing.T) {
 	})
 	be.Equal(t, 6, result)
 }
+
+func TestIgnoresTooBig(t *testing.T) {
+	result := ks.MaxValue(1, []ks.Book{
+		{Weight: 10, Value: 4},
+		{Weight: 1, Value: 1},
+	})
+	be.Equal(t, 1, result)
+}