Work in your own Odin directory 2010/3/
Name this program guess.cpp

Ask the user to pick a number from 1 to 10.

Read the number into an integer.
Use a compound boolean expression for validation.
If the number is out of range, print an error message and exit the program. If in range, show the number entered on the screen.

Run the program multiple times to make sure you are validating the input correctly. Try entering a negative number, then try 0, then try 1, then try 10, then try 11, and so on. Testing 0, 1, 10, and 11 is called boundary testing to make sure the program behaves correctly when the input switches from bad to good and vise versa.

Running your program will look something like this...

Number guessing game.

Enter a number from 1 to 10: 6

Your number was 6, but the secret number was 3.
Sorry, you lose.

Turn your program into a game...

Start a new program named: game.cpp

Have your program generate a "secret number" that you do not know.

Seed the random number generator: srand(time(NULL));
Generate a random number from 1 to 10.
Store it in an integer.
Compare the user's input to this number.
Display "winner" or "loser" based on the result.

Use the rand() function to get a random number.
Use the modulus operator to control the range.
  Example: rand() % 2 produces an integer between 0 and 1.
  Example: rand() % 100 produces an integer between 0 and 99.
  Example: rand() % 100 + 1 produces an integer between 1 and 100.

Add this statement: #include <cstdlib> near the top of your program.
Refer to your textbook for help with the rand() function.

Your program will look like this...

Number guessing game.

Enter a number from 1 to 100: 60

Your guess is low. Try again: 85

Your guess is high. Try again: 81

Winner!!!
It took you 3 tries.

Setup a menu to get user input.

Work in Odin directory 2010/3/
Name this program menu.cpp

Your program will display a menu such as below.

lab3 menu
--------------------------------------
1. calculate area of a rectangle
2. calculate area of a triangle
3. calculate surface area of a sphere
q. quit
--------------------------------------
Enter your selection:

   $ cp menu.cpp menuloop.cpp

Homework requirements
---------------------

1. Finish the 4 programs from the lab day.

2. Finish the monday.cpp program.

3. Some modifications to the programs...

   guess.cpp
      · No looping is allowed.
   
   game.cpp
      · Use the while-loop to make your program into a game.
      · Set the secret number range from 1 to 100 exactly.
      · Inside your while() loop, place the following statement...
          usleep(10000);

   menu.cpp
      · No looping allowed in this program.
      · Leave the 1, 2, 3 and q as the menu selections.
      · For area of a rectangle, prompt for width and height.
      · For area of a triangle, prompt for base and height.
      · For surface area of a sphere, prompt for radius.
      · No extra input.
   
   menuloop.cpp
      · This program is required as homework.
      · It will work just like menu.cpp, except it will show the menu
        again and again until the user enters 'q'.
      

4. Look at the monday page, and finish that program.


Due before our next lab.

  guess.cpp
  game.cpp
  menu.cpp
  menuloop.cpp
  monday.cpp

Your instructor will run your programs like this...

    ./a.out < input

so keep your user input just as shown.