Debug the following program to calculate N!

#include

using namespace std;

main()

{

            int N, factorial=1;

            cout << "Enter a positive integer"

            cin >> N;

            for(int i=N; i>=1; factorial *= --i);

            cout << N<<"!="<

return 0;

}

What was wrong?

2  Set N='A'. What is the result? Does it make sense? Modify the program to make sure that the entered value is numeric. You can do so by using cin.fail() and cin.clear() (see the following for more information.

Also, modify the program such that it does not accept negative numbers and insists on getting a positive value for N. You can do so by using a while loop that keeps asking for a positive integer till a positive integer is entered.

3  Get your code to compute 1!,2!,5!, and 25!. Are you getting the correct answer for all of the entered values? If not, what went wrong? Would you be able to fix this by changing the variable type? Explain your answer.