Update apple.cpp

Author: Light-City

basic_content/const/class_const/overload_example/apple.cpp

@@ -6,7 +6,7 @@ class Apple
     Apple(int i);
     static const int apple_number;
     void take(int num) const;
-    int add(int num);
+    int add();
     int add(int num) const;
     int getCount() const;
 };