add day 2 to main.go and simplify input reading

main.go

@@ -21,35 +21,28 @@ var (
 	// slice of all puzzles
 	puzzles = []puzzle{
 		&day01{},
+		&day02{},
 	}
 )
 
-func inputs(day int) [2]io.Reader {
-	inputs := [2]io.Reader{}
-	path1 := fmt.Sprintf("input/%d-1", day)
-	path2 := fmt.Sprintf("input/%d-2", day)
-
-	f1, err := os.Open(path1)
-	if err == nil {
-		inputs[0] = f1
-	}
-	f2, err := os.Open(path2)
-	if err == nil {
-		inputs[1] = f2
-	}
-	return inputs
-}
-
 func main() {
 	flag.Parse()
 	puzzleIndex, err := strconv.Atoi(*day)
 	if err != nil {
 		log.Fatalf("invalid puzzle day: %s", *day)
 	}
-	inputs := inputs(puzzleIndex)
 
 	puzzle := puzzles[puzzleIndex-1]
 
-	fmt.Fprintf(os.Stdout, "Solution 1:\n%s\n", puzzle.solve1(inputs[0]))
-	fmt.Fprintf(os.Stdout, "Solution 2:\n%s\n", puzzle.solve2(inputs[1]))
+	path1 := fmt.Sprintf("input/%d-1", puzzleIndex)
+	path2 := fmt.Sprintf("input/%d-2", puzzleIndex)
+
+	f1, err := os.Open(path1)
+	if err == nil {
+		fmt.Fprintf(os.Stdout, "Solution 1:\n%s\n", puzzle.solve1(f1))
+	}
+	f2, err := os.Open(path2)
+	if err == nil {
+		fmt.Fprintf(os.Stdout, "Solution 2:\n%s\n", puzzle.solve2(f2))
+	}
 }