CS202 -- Lab 0 (Spring 2024)


Inspiration

This is a simple assignment to help knock off any rust and reinforce accessing the lab systems remotely, compiling on the command line, simple I/O, and using ASCII to process chars as ints.

This is mostly verbatim from Dr. Plank's version, since it was recommended by Dr. Marz to "onboard" my original cohort (the old CS140) and it was equally useful last fall even though they (and you!) all had a more in-depth CS102. I also expect it to be easily finishable during lab using your prior experience and lecture notes (if needed) with most of the effort getting used to the gradescript methods (see below). My main function is 10 lines excluding brackets and blank space(s) added to improve readability of my solution.

Originial version here: https://web.eecs.utk.edu/~jplank/plank/classes/cs202/Labs/Lab0/

Rubric

This lab is practice, and as such will only earn you participation points. Don't worry about commenting too much as we'll largely using this to make sure you are able to use the lab systems for the more challenging later assignments. We'll run this expecting nearly all of them will compile and pass and reach out if it doesn't.

  1. +0.5 Uses input from cin properly
  2. +1 Solves all of the gradescripts

I'm going to require solving all of the grade scripts as my version inspired by Dr. Plank's notes solves them all once map2.txt was solved (by intentionally including a potential bug in my initial solution). And the main goal of this lab is to give you practice using the legacy grading scripts since we'll use "automated grading" in different forms throughout the next two semesters. This approach is not perfect -- it often focuses on getting things right vs. coding well -- but as we'll discuss in class the goal here is to enable transparent grading; you will know how your code performs (aka your lab score) before you submit it.

If you don't you have time to finish it in lab, then finish it on your own, and submit it by the deadline on Canvas. We recognize everyone works at their own pace. After this in-class lab, you'll be doing larger projects and coming to lab for help in more of a programming clinic-style.

The program that you should write: gold.cpp

This program reads a "map" on standard input. It's really a text file in the following format: For example, the following map in map1.txt contains a lot of dirt, but it also contains one rock with nothing under it, and three rocks with gold: one ounce (A), three ounces (C) and 26 ounces (Z).

...............
..-............
.........A.....
..Z.........C..

Your job is to write a program called gold.cpp, which reads a map on standard input and prints the total ounces of gold on the map.

There is an example executable in gold. Try it out:

UNIX> cd /home/jplank/cs202/Labs/Lab0
UNIX> bin/gold < data/map1.txt
30
UNIX> cat data/map2.txt
ABCDE.
.F----.
--...........G
UNIX> bin/gold < data/map2.txt
28
UNIX> 

Testing and Grading for Correctness

There are two programs that you should use for testing and grading. The first is gradescript. You can call it from the lab directory, and you call it with a number between 1 and 100. This will execute your gold program. You need to have your gold executable in a subdirectory called "bin" (e.g., bin/gold), and call the gradescript as shown later.

You can examine the input file with cat or more, or even vi:

UNIX> cat /home/jplank/cs202/Labs/Lab0/Gradescript-Examples/001.txt
A
UNIX> 
Let us suppose that you made a mistake writing gold, and that instead it is a program that always prints "1":
UNIX> mkdir bin
UNIX> cp retone.cpp bin
UNIX> cat bin/retone.cpp
#include <iostream>
using namespace std;

int main()
{
  cout << "1\n";
  return 0;
}
UNIX> g++ -o bin/gold bin/retone.cpp
UNIX> 
When you run problem one on it, it works fine, because "1" is the proper output for the first problem. However, it fails on problem 2:
UNIX> /home/jplank/cs202/Labs/Lab0/gradescript 1
Problem 001 is correct.

Test: ./gold < /home/jplank/cs202/Labs/Lab0/Gradescript-Examples/001.txt
UNIX> /home/jplank/cs202/Labs/Lab0/gradescript 2
Problem 002 is incorrect.

Your standard output does not match the correct one.

TEST:

./gold < /home/jplank/cs202/Labs/Lab0/Gradescript-Examples/002.txt

FILES:

Your standard output is in tmp-002-test-stdout.txt.
Your standard error  is in tmp-002-test-stderr.txt.

The correct standard output is in tmp-002-correct-stdout.txt.
The correct standard error  is in tmp-002-correct-stderr.txt.

Look at correct files and your files, perhaps run 'diff -y' on them, and figure out your mistake.
Please remember to delete this files when you are finished.
UNIX> 
You can examine your output and the proper output in the files listed:
UNIX> cat tmp-002-test-stdout.txt
1
UNIX> cat tmp-002-correct-stdout.txt
30
UNIX> cat /home/jplank/cs202/Labs/Lab0/Gradescript-Examples/002.txt
...............
..-............
.........A.....
..Z.........C..
UNIX> 
That way, you can try to find your errors. In most cases, your output must match the test case exactly. That can be a challenge.

The script gradeall checks your programs in 100 test cases:

UNIX> /home/jplank/cs202/Labs/Lab0/gradeall
Problem 001 is correct.
Problem 002 is correct.
Problem 003 is correct.

...

Problem 099 is correct.
Problem 100 is correct.

100 Correct out of 100
UNIX> 

When you have written gold.cpp correctly, you may submit it by uploading this single file, named this exact way, onto Canvas.

If you need help copying files over and/or a refresher in Unix, please refer to this guide written by former GTA Clara:

Unix/SCP Guide