ECE-C301 Advanced Programming for Engineers
Laboratory Assignment: Week 6
Name:
(10 Points) The following table shows telephone area codes in the state of Georgia along with the largest city in
each area:
Area Code Major City
229 Albany
404 Atlanta
470 Atlanta
478 Macon
678 Atlanta
706 Columbus
762 Columbus
770 Atlanta
912 Savannah
Write a switch statement whose controlling expression is the variable area code. If the value of area code is in
the table, the switch statement will print the corresponding city’s name. Otherwise, the switch statement will
display the message “Area code not found.” Use case “fall throughs” in order to simplify the switch block as
much as possible.
TA Initials
(20 Points) The following prime number test is not very efficient:
1 int is_prime (int n)
2 {
3 int d;
4
5 for (d = 2; d < n; d++) {
6 if (!(n % d))
7 return 0;
8 }
9
10 return 1;
11 }
It is unnecessary to divide n by all numbers between 2 and n -1 to determine if it is prime. Only divisors up to
√
n need to be checked. Make this change. Next, write a simple main() function that uses a for-loop and your
improved implementation of is prime() to compute the first 25 primes (starting with 2). Show your program to
the TA.
Note: Computing a square root takes much longer than computing a square. So, instead of computing √
n, compare
d × d with n.
TA Initials
1
