The purpose of lab today is to get you familiar with more code and to solidify your understanding of concepts done in lecture by hand, like our greedy subtraction algorithm to turn base 10 numbers into binary numbers.

1 Getting Started

Download the binary.c file off the course webpage under the lab subdirectory. (Remember the linux command to do this from the last labs?)

To compile the code, use the following command.

2 Adding to the code

• First, create a function to read in a base-10 number from standard in. This function should return an int. You should largely be taking code from last lab and slightly modifying it.
• Next, write a function that takes in a positive base-10 integer and prints out the corresponding (unsigned) binary string. This function needs to use the greedy subtraction algorithm we used in class. All binary strings should be length 16.
  • To test this function, include some testing code in your main method. Create two files testbinary.in and testbinary.out. These files will need to have an interesting number of correct testing cases in order to get credit for having completed this step. Use the function created in the first step to read in numbers from this file, and then print out the binary string.
• Edit the function from above to print out an error message if passed an integer that is larger than your binary string (unsigned) can handle.
  • Include some test casees for this step in your text files. This step will only be considered to be complete with corresponding test cases.

3 More time?

• Create a function that reads in a base 16 number (that starts with a 0x) and returns the corresponding integer value. You should do this a similar way that your function that reads in base 10 numbers.
• Can you instead write a general function that reads in base-n numbers and turns them into integers? Assume that the line in structured as follows (note the lack of white space, except for the new line character at the end of the line):
  (base)number

  Write some test cases for this.

• Can you write a similar greedy subtraction algorithm that takes in a postive base-10 integer and prints out the corresponding string in any base? Have this function return an error if any passed number is larger than 65,535 (why did I pick this number?). Write some additional test cases for this.

4 Turning in your program

It’s ok not to finish this assignment – get through as many test cases as you can.

Zip up your binary.c file along with your test cases into a zip file entitled yourCSUsername.zip. Then drop the zip file into the lab-03 folder in the dropbox.