Grading: Each programming problem is graded as follows
• A submission which does not compile gets 0.
• A submission which compiles but does something completely irrelevant gets 0.
• A submission which works (partially) correctly, gets (up to) %80 of the total credit.
• %20 is reserved for the coding style. Follow the coding style described in the book.
Problem 1 [15pts]. Write a program that computes the slope of a line given two of its points on the plane. In more detail, the program reads (from keyboard) two points p = (xp; yp) and q = (xq; yq), and computes the slope m of the line that crosses p and q using the following formula
m =
yq
yp
:
xq
xp
You program should first check to see if xq = xp in which case it should print ”The line is vertical!” Below are two examples of how the program should behave
Example 1:
Enter the x-value of the first point: 3
Enter the y-value of the first point: 10
Enter the x-value of the second point: 7
Enter the y-value of the second point: 20
The slope of this line is 2.5
Example 2:
1
Enter the x-value of the first point: 22
Enter the y-value of the first point: 10
Enter the x-value of the second point: 22
Enter the y-value of the second point: 20
The line is vertical!
Note that you must compute the slope as a floating-point number.
Problem 2 [20pts]. Write a program that inputs the name, quantity, and price of three items. The name may contain spaces. Output a bill with a tax rate of %6:25. All prices should be output to two decimal places. The bill should be formatted in columns with 30 characters for the name, 10 characters for the quantity, 10 characters for the price, and 10 characters for the total. Sample input and output are shown as follows:
Input name of item 1:
lollipops
Input quantity of item 1:
10
Input price of item 1:
0.50
Input name of item 2:
diet soda
Input quantity of item 2:
3
Input price of item 2:
1.25
Input name of item 3:
chocolate bar
Input quantity of item 3:
20
Input price of item 3:
0.75
Your bill:
Item
Quantity
Price
Total
lollipops
10
0.50
5.00
diet soda
3
1.25
3.75
chocolate bar
20
0.75
15.00
Subtotal
23.75
6.25 percent sales tax
1.48
Total
25.23
2
