CS50 Coding Contest 2016

My solutions for cs50's coding contest on hacker rank, June 28th to August 1st 2016. Solutions for "airport arbitrage" and "trading up" still missing a few test cases.

Problem Sets

Each problem set has its own directory, and in each is a README.md file with both the problem statement and the solutions (i.e. the postmortems), as well as the C source code file implementing the solution. For running the compiled programs or building them directly on your host OS see the Compiling section below.

Compiling

Below are the compilation options which will be discussed in detail. While it is possible to use the make command directly on your host OS, you will likely find it much easier to simply use the Docker image containing the precompiled binaries for your processor architecture. Visit the Docker section to learn more or the Make section to compile directly on your machine.

Docker

A multi-arch Docker image is available at ghcr.io/ragingtiger/cs50_coding_contest_2016:master and has all the binaries compiled and ready to use. The different use cases will be presented and discussed below.

Run

Quite possibly the easiest way to run the binary executable files is by simply executing docker run. First to see the names of the binaries, execute the following:

docker run --rm \
           ghcr.io/ragingtiger/cs50_coding_contest_2016:master \
           ls /usr/local/bin

This will print out a list of all the binaries:

airport_arbitrage
maze_runner
money
name_your_cat
one_day_more
punctuation
trading_up
wait_for_it
word_reverse
x

Login Shell

From here you have two choices either execute ash and run your program of choice (e.g. word_reverse):

docker run --rm \
           -it \
           ghcr.io/ragingtiger/cs50_coding_contest_2016:master \
           ash

and then:

/ # word_reverse
all work and no play make jack a dull boy
lla krow dna on yalp ekam kcaj a llud yob

Run Directly

Or just directly run the executable program (e.g. punctuation):

docker run --rm \
           -it \
           ghcr.io/ragingtiger/cs50_coding_contest_2016:master \
           punctuation

Your choice, depending on what is best for your use case.

Make

A Makefile is provided to make it easier to compile all the binaries. Below are the commands defined in the file. Also, depending on your target OS, you may need to pass different compilation and/or linking arguments to the compiler (here the default is gcc). This can be done using the CFLAGS and LDFLAGS variables as follows:

# example compilation and linking args
make subcommand CFLAGS='-static -Wall' LDFLAGS='-lm'

All

Simply run make and all the binaries will be compiled into their respective subdirectories (i.e. Punctuation/punctuation, Maze_Runner/maze_runner, etc ...). For example download the repo and execute the following:

cd cs50_coding_contest_2016
make

Now to run name_your_cat simply execute:

./Name_Your_Cat/name_your_cat

Install

This subcommand allows you to build all the binaries but also install them into a single directory called bin:

make install

When you ls bin/ you will see all the binary files now in one convenient directory.

Clean

To cleanup (i.e. remove all binaries) simply run:

make clean