CISC105 Fall 2006 Lab03

• Write a program for each of the following problems. Be sure to save every separate program. All programs must be properly commented and indented (see Assignment Standards on the class website).
  
  
• Familiarize yourself with the website's section on Academic Honesty. I require strict adherence to this policy, and I will pursue any violations through the University's process outlined in the student manual online. If you are freaking out about getting a lab done, come see your prof or TA, even if it means being a day or two late - the penalties for lateness are much nicer than the penalties for sharing code or otherwise cheating.
  
  
• Any time you expect user input, you must print a prompt telling the user what to enter.
  
  
• Name each program lab03.n.c, where n is the number in the list below. For example, the name of the file for the first will be lab03.1.c. Put the files in your lab03 directory.
  
  

Programs

1. Write a program with a function that will print a line of n asterisks on a single line. You may only have a single print statement that prints a single asterisk! Ask the user how long the line should be, and print it. Repeat until the user enters a length of -1. (So -1 is a ???.)

    
   > ./a.out
   How long would you like your line? 6
   ******
   How long would you like your line? 3
   ***
   How long would you like your line? -1
   Goodbye!
   >
   
   

   Hint: first code the loop that will print the line in your main(). Then take the code outside of main() and place it in a definition. (What other two things will you need to add?) Once you have a function that prints a line, then put a call to it in main(), and put a loop around the call.
   
   
2. Write a program with an array of twenty integers. Use a loop to set the values of the array to the even numbers 0,2,4,6,8,...38. Note that you do not need to use scanf to do this (why not?). Use another loop to print the array on a single line with a space between each number.
   
   
3. Copy the program from problem 2. Make a program with an array of fifty integers. Use a loop to set the values of the array to the multiples of three, starting at zero. Use another loop to print the array, but with two differences. Use a conditional inside the loop to insert a newline (backslash followed by the letter n) after every tenth number (this is similar to the kind of problem you solved in lab02.10), and use formatting information (H&K 2.6) to line up the numbers in columns as shown:

    > a.out 
     0   3   6   9  12  15  18  21  24  27 
    30  33  36  39  42  45  48  51  54  57 
    60  63  66  69  72  75  78  81  84  87 
    90  93  96  99 102 105 108 111 114 117 
   120 123 126 129 132 135 138 141 144 147 
   
   

   
   
   
4. Copy the program you made for problem 1. Modify the function to make a square of asterisks. This time, instead of looping up to the user input number, loop until the input number squared (i.e. print enough asterisks to fill a square of size "input"). Once that is working, put a statement inside the loop that uses a conditional to print a single newline. The condition should be true when the loop reaches the end of one line of a square. For example, if the user enters "6", then the program will print 36 separate asterisks with a newline after every sixth asterisk.

    
   > ./a.out
   How big would you like your square? 3
   ***
   ***
   ***
   How big would you like your square? -1
   Goodbye!
   >
   
   

   
   
   
5. Copy (again!) the program you made for problem 1. Using the same function you wrote for that problem, you will now make a square of asterisks. Write another function that will get called from main() with the size of a square. If the size of the square is to be four, it will call the asterisk line function from problem 1 four times.

    
   > ./a.out
   What size would you like your square? 4
   ****
   ****
   ****
   ****
   What size would you like your square? -1
   Goodbye!
   >
   
   

   
   
   
6. Declare an array of 10 doubles. Write a while loop that takes up to 10 numbers entered by the user (how will you get the input?) until the user enters a negative number or the array is filled. After the data is all entered, use a loop to sum the values in the array. A negative number should not be entered in the array or become part of the sum. Print the sum only once, after the loop is finished. Demonstrate your program using the decimals 4.0, 4.1, 4.2, ... 4.9 inclusive.
   
   
7. As you program, practice all of your Unix commands that have been introduced in lab and class: ls, pwd, cd, cp, rm, mv, and mkdir because they will be on the exams.