Chapter 5, Problem 7E

Program 5.10 has several inefficiencies. One inefficiency results from checking even numbers. Because it is obvious that any even number greater than 2 cannot be prime, the program could simply skip all even numbers as possible primes and as possible divisors. The inner f loop is also inefficient because the value of p is always divided by all values of d from 2 through p-1. This inefficiency could be avoided by adding a test for the value of i in the conditions of the f loop. In this manner, the f loop could be set up to continue as long as no divisor was found and the value of d was less than p. Modify Program 5.10 to incorporate these two changes. Then run the program to verify its operation. (Note: In Chapter 6, you discover even more efficient ways of generating prime numbers.)