created 07/29/99

Chapter 13 Programming Exercises

Exercise 1 --- Internet Delicatessen

Sam and Ella's Delicatessen wants a program to take orders from the internet. The program will ask what item the user wants, will ask its price, and will ask if the user wants overnight shipping. Regular shipping for items under $10 is $2.00; for items $10 or more shipping is $3.00. For overnight delivery add $5.00.

Enter the item:
Tuna Salad
Enter the price:
450
Overnight delivery (0==no, 1==yes)
1

Invoice:
  Tuna Salad    4.50
  shipping      7.00
  total         11.50

(A real internet order form would use different I/O methods than the ones you will use for this program.)

Exercise 2 --- Steam Engine Efficiency

The maximum possible efficiency of a steam engine depends on the temperature of the steam in the boiler and the temperature of the outside air:

efficiency = 1 - Tair / Tsteam

where Tair is the air temperature and Tsteam is the steam temperature. The temperatures are give in degrees above absolute zero. Normal air temperature is about 300^oK. Boiling is 373^oK. Write a program that asks the user for the air temperature and the steam temperature and writes out the maximum possible efficiency of a steam engine. However, if the steam temperature is less than 373^oK there is no steam, so the efficiency is zero.

Use integer or floating point input, but do the calculations in floating point.

Exercise 3 --- Microwave Oven

A microwave oven manufacturer recommends that when heating two items, add 50% to the heating time, and when heating three items double the heating time. Heating more than three items at once is not recommended.

Write a program that asks the user for the number of items and the single-item heating time. The program then writes out the recommended heating time.

Hint: do this with four successive single-branch if statements each of which tests for one of the four cases: 1 item, 2 items, 3 items, more than three items. Look at the sports car purchase program in the chapter to see how to do this, if you are stuck.

Exercise 4 --- Fantasy Game

In a new role-playing fantasy game players get to design their character by picking a point value for each of three characteristics:

Strength, from 1 to 10
Health, from 1 to 10
Luck, from 1 to 10

Write a program that asks for a name for the character and asks for the point value of for each of the three characteristics. However, the total points must be less than 15. If the total exceeds 15, then 5 points are assigned to each characteristic

Welcome to Yertle's Quest
Enter the name of your character:
Chortle
Enter strength (1-10):
8
Enter health (1-10):
4
Enter luck (1-10):
6

You have give your character too many points!  Default values have been assigned:
Chortle, strength: 5, health: 5, luck: 5

(This user interface could get much more complicated. You might want to implement some of your own ideas.)