The factorial of a positive integer N, denoted by N!, is defined by the following:

N! = 1 × 2 × . . . × N (Note: 0! = 1 )

Using subprograms and functions, create a recursive program to compute N!. The user should input a positive integer and a subprogram should check that the input is correct (a positive integer). Then use recursion to compute the factorial. Create a subprogram that will call itself to do the multiplication until N = 1. Then display the result in the main program.