fix(hiddenp): solution not complient to subject

Author: MSilva95

solutions/hiddenp/main.go

@@ -8,6 +8,9 @@ import (
 
 func main() {
 	var i int
+	if len(os.Args) != 3 {
+		return
+	}
 	for _, r := range os.Args[1] {
 		j := strings.Index(os.Args[2][i:], string(r))
 		if j == -1 {