Programming Assignment Solution

Instructions
Submit on Canvas a tar le named lastname.tar (where lastname is your last name) that contains all of the required les. Don't submit any other les (e.g., test case or pyc les).




Here is an example of what to submit:




hampton.tar




README




my class1.py




my class2.py




my class3.py




problem.py




another problem.py




...




Note that Canvas might change the name of the le that you submit to something like lastname-N.tar. This is totally ne!

The grading for this assignment will be roughly as follows:




Task


Points












System Tools Warmup


participation credit






I/O Warmup


participation credit






Submit Warmup


participation credit












TOTAL


participation credit








Warmup Problems



Problem 1. System Tools Warmup




This problem will let you practice with some essential system utilities.




Before you start, you will need to set up a CIS Department systems account (if you don't already have one).




You can stop by the department o ce in Deschutes Hall or use the following self-service link:




https://systems.cs.uoregon.edu/wiki/index.php?n=Help.Account




Reference the Lab 1 Notes for the terminal commands needed to complete this problem.




Log onto ix-dev and create a new directory named CIS313. Inside that directory create another directory named pset0. Go into the CIS313/pset0 directory and copy the instructions for this problem, given by the following path, into your current directory:




/home/users/hampton2/lab1 313/instructions







Alternately, you can download the instructions from the following link:




http://ix.cs.uoregon.edu/~hampton2/313/instructions




View the contents of the instructions le to complete this problem.






Problem 2. I/O Warmup




Download the Programming Assignment 0 starter pack here:




http://ix.cs.uoregon.edu/~hampton2/313/proj0_starter.tar




Unpack it with the tar command (reference the Lab 1 Notes for help if needed).




The starter pack contains two Python 3 les: a Calculator class and a driver program. You won't be required to use Python to complete the course assignments, but it's strongly encouraged! Python is a great language to know right now for succeeding with tech interviews.




The calculator class has already been written for you. It implements the following (public) methods:




add(X): Takes a single integer argument and adds it to the running total. Should be amortized O(1) time.




mult(X): Takes a single integer argument and multiplies the running total by X. Should be amortized O(1) time.




seen(X): Takes a single integer argument and returns a boolean indicating whether the running total has ever been equal to X. Should be amortized O(1) time.




The driver program has also already been written for you! It takes a single command-line argument, which will be a lename. The input le will contain instructions for calculator operations. The rst line of the input le will be an integer 1 N 103 giving the number of instructions. Following will be N lines, each containing an instruction. The possible instructions are:




plus X, where 106 X 106 is an integer: For this instruction, add X to the running total. Output the running total.




times X, where 0 X 103 is an integer: For this instruction, multiply the running total by X. Output the running total.




seen X, where 107 X 107 is an integer: For this instruction, give an indication of whether the running total has ever been equal to X. Output YES if the running total has ever been equal to the given value, else output NO.




All output should be to STDOUT. Each piece of output should be separated by a newline.




Example input le:




9




times 200




plus 1




plus 2




seen 5




seen 0




times 5




seen 5




seen 3




seen 15




Example output:







3



0




1




3




NO




YES




15




NO




YES




YES




The starter pack also includes sample input and output les. Your programming assignments will be graded on ix-dev, so you want to be sure that your code works on there. Send your source les over to ix-dev (e.g., using the scp command) and run them there. The Python 3 interpreter on ix-dev is invoked as python3.




There is a system utility called diff that is super helpful for seeing if two les match. The diff utility will even catch whitespace di erences that are easy to miss.




It's often convenient to save the output from a program to a le. We can do that with the redirection operator:




python3 driver.py sample.input my output







Note that le extensions (such as .txt) aren't as strict on a UNIX-like system as they are on, say, Windows. We can typically use whatever extensions we want. If you want the system to tell you what kind of le you've got, use the file utility:




file my output







Now, let's compare my output and sample.output:







diff my output sample.output







If you run the diff command and don't see anything in the terminal, that means it was a perfect match! You'll notice, however, that we don't have a perfect match. Use a reference to help you learn how to read the results of diff.




The Calculator class and driver class were implemented for you, but there are two bugs that need to be xed! The bugs were caught during code review, so read the les and implement the two xes that are suggested in the comments.




Once you've got a solution that produces a perfect match according to diff, you're done with this problem.




[Just for fun: if you just want to compare the output of a program with a le, it's not necessary to create a temporary le. The pipe operator allows you to use the output from one command as the input to another command:




python3 driver.py sample.input | diff - sample.output




This is just a brief intro to UNIX system utilities. Learning to use these tools to automate system jobs will save you a lot of time down the road!]




Problem 3. Submit Warmup




In this problem, you'll get practice bundling your submission into a tar le and uploading it to Canvas.




Navigate to your CIS313/pset0 directory on ix-dev. Create a new directory called submit.




Copy into this new directory (either from elsewhere on ix-dev or from your personal computer) everything that you need to turn in. For this assignment, it's the following les:




problem1_solution




calculator.py




driver.py




It's a good idea to go through the steps from Problem 2 to test your solution again. It's easy to avoid accidentally submitting the wrong les.




Once you're sure you've got the correct les, write a README for your project. Remember, you can use the following command to create a new le called README and open it in the nano editor (feel free to use a di erent editor if you prefer):




nano README




Your README should contain your name and exact commands that can be invoked on ix-dev to run your solution for each problem. If your solution takes an input le, just use a dummy name. For example, your README for this project should look something like this:




Andrew Hampton




Problem 2: python3 driver.py some.input




If you use a language that requires compilation, your README should also include the exact commands to build your project on ix-dev.




Finally, create a tar le that contains everything you want to submit. In the lename lastname.tar, replace lastname with your last name:




tar cvf lastname.tar problem1 solution calculator.py driver.py README







You can check that the le you've created is actually a tar le by using the file command:




file lastname.tar




Now, just copy the tar le back to your personal computer and upload it to Canvas for Programming As-signment 0.




This is how you will turn in all of the programming projects for this course (and most of your upper division CIS courses). It's important to follow these instructions because it allows parts of the grading process to be automated. You will lose a substantial amount of credit for an assignment if you don't follow the submission guidelines or submit the wrong les.

























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