C++

Write the code of a program that calculates n! (Faculty calculation). The integer n is read from the user. Example: If the user enters the number 5, the program will calculate the product 1 * 2 * 3 * 4 * 5. The program should provide an error message if the user specifies a negative integer. Special case: 0! = 1 by definition.

Given the following template:

Int main () { Int n; Return 0; }