Problem
Compare the running times1 for the recursive factorial function written in this section with a nonrecursive function obtained by initializing a local variable to 1 and using a loop to calculate the product n! = 1 × 2 ×···× n. To obtain meaningful comparisons of the CPU time required, you will probably need to write a loop in your driver program that will repeat the same calculation of a factorial several hundred times. Integer overflow will occur if you attempt to calculate the factorial of a large number. To prevent this from happening, you may declare n and the function value to have type double instead of int.