Как определить массив, размерность которого определяет пользователь после запуска программы на выполнение?

Попробуйте запустить программу с delete[] и с delete

я пробовал Ничего не заметил Вот и спросил Как можно проверить

Добавлено через 17 секунд
вы сказали "никак"

Как проверить??

5.3.5
1. The delete-expression operator destroys a most derived object (1.8) or array created by a new-expression.
delete-expression:
::optdelete cast-expression
::optdelete [ ] cast-expression
The first alternative is for non-array objects, and the second is for arrays. Whenever the delete keyword
is immediately followed by empty square brackets, it shall be interpreted as the second alternative.76
The operand shall have a pointer to object type, or a class type having a single non-explicit conversion
function (12.3.2) to a pointer to object type. The result has type void.
2. If the operand has a class type, the operand is converted to a pointer type by calling the above-mentioned
conversion function, and the converted operand is used in place of the original operand for the remainder of
this section. In the first alternative (delete object), the value of the operand of delete may be a null pointer
value, a pointer to a non-array object created by a previous new-expression, or a pointer to a subobject (1.8)
representing a base class of such an object (Clause 10). If not, the behavior is undefined. In the second
alternative (delete array), the value of the operand of delete may be a null pointer value or a pointer
value that resulted from a previous array new-expression.78 If not, the behavior is undefined. [ Note: this
means that the syntax of the delete-expression must match the type of the object allocated by new, not
the syntax of the new-expression. —end note ] [ Note: a pointer to a const type can be the operand of a
delete-expression; it is not necessary to cast away the constness (5.2.11) of the pointer expression before it
is used as the operand of the delete-expression. —end note ]

то мы "разорвем массив", а это уже серьезный косяк.