# Lab 1

## Logistics

• Due: Wednesday, May 12th no later than 11:59pm.
• Submission instructions: push a commit with the tag lab1 to your git repository.
• Deadline reminder: after the deadline passes, you cannot earn any points for this assignment. If the deadline is approaching, submit what you have in order to earn partial credit.

## Learning outcomes

• Practice using if and/or switch statements.
• Practice using functions to organize your code.
• Get input from the user.
• Practice writing complicated output.

## Assignment

This comes from problem 1, chapter 4 on page 232-233.

A store provides discounts for the military based on the dollar amount of the purchase. In this program, you will prompt the user for the dollar amount purchased and whether they are in the military or not. The program will then determine the discount, sales tax cost and total. It will print out this information in a neat way.

If a person is in the military, they get a 15% discount if they spend $150 or more. The discount for military is 10% otherwise. If they are not in the military, they get no discount. Everyone pays a 5% sales tax on purchases of any amount, but the 5% sale tax is applied after any discount. ### Requirements • Write your program in a file called lab1.c in your csci112-firstname-lastname/labs/lab1/ directory. • Accept only n, N, y, and Y for input as to whether the person is in the military or not. For any other input, print Error: bad input and end the program. (Note: actually, as long as you are using only the data types that we have learned about so far (int, double, and char, you can accept any inputs beginning with those four characters; for example, no would also work. If you can explain why this is, you can get extra credit. See the Grading section.) • Use a separate function to compute the discount. • Use a separate function to print the results. (This function can call the function that computes the discount if you like.) • Your output formatting must match the example. Use a tool like diffchecker to compare your output with the sample output. Don’t worry about trailing spaces. ### Example output [p19t655@csci112 lab1]$ ./lab1
Cost of purchase?		$217 In military (y or n)? y Military discount (15%):$32.55
Discounted total:		$184.45 Sales tax (5%):$9.22
Total:				$193.67 [p19t655@csci112 lab1]$ ./lab1
Cost of purchase?		$80 In military (y or n)? Y Military discount (10%):$8.00
Discounted total:		$72.00 Sales tax (5%):$3.60
Total:				$75.60 [p19t655@csci112 lab1]$ ./lab1
Cost of purchase?		$115 In military (y or n)? n Sales tax (5%):$5.75
Total:				$120.75 [p19t655@csci112 lab1]$ ./lab1
Cost of purchase?		$20 In military (y or n)? x Error: bad input [p19t655@csci112 lab1]$ ./lab1
Cost of purchase?		$20 In military (y or n)? No Sales tax (5%):$1.00
Total:				\$21.00


### Hints

• If you are having trouble reading in a char, you may need to add a space so that scanf doesn’t consume whitepsace from a previous printf. See this stackoverlow post.
• Use \t to add tabs to your output.
• To print a %, use the format %%. For example, printf("5%%") would print 5%.

• 10 points – code is indented so it is readable
• 10 points – compiles successfully with -Wall – no warnings
• 5 points – discount is computed in own function
• 5 points - a separate function is used to print the results
• 20 points – uses proper math equations to compute taxes and discount
• 10 points – prints the output to exactly match the sample output
• 10 points – reads in the input to exactly match the sample
• 10 points – allows y, Y, n, N as input for military question
• 10 points – prints error message if any other input for military question, exactly matching example
• BONUS: 5 points - in a comment in your program, explain why your program can accept longer strings of characters as long as they begin with y, Y, n, or N.