These are Python solutions for the book Cracking the Coding Interview, 6th Edition by Gayle Laakmann McDowell.

To run the programs, just use the python chapter_X/filename.py command.

To run the tests: pip install pytest and pytest

Contributions welcome! Please submit separate pull requests for each solution you work on.

In general solutions should fall into one of the following three categories:

• algorithm demonstration. This is the primary type of problem and solution that the text is concerned with. As such, solutions should not use standard library functions in cases that would make it unnecessary to implement the algorithm. The goal of these solutions should be to have an easy to understand solution that demonstrates understanding of the algorithm.
• python demonstration. We also accept solutions that solve the problem in a more practical way, using whatever standard library functions are available. Please do not use any third party dependencies. These solutions should also be easy to understand and good examples of pythonic ways of doing things.
• speed demonstration. These alternative solutions may be accepted if the fastest way to do something is not very readable or intuitive and thus it doesn't fit into the first two categories.

If you want to do everything really well, here are some guidelines. Solutions should:

• work with Python 3.6 or greater
• not depend on third-party libraries (like numpy)
• follow python style conventions
  • lower_case_with_underscores for everything except classes
  • descriptive, longer variable names
• be formatted using the black code formatter
• include tests to prove they work. pytest is supported
• have a clean commit history ideally following the angular commit message convention and including the problem being worked on in parenthesis. For example feature(C01_P04): added solution. The C01_P04 referring to Chapter 1, Problem 4. Look at our commit history for more examples:

We'll still work with your contributions even if they don't follow these guidelines so don't let that stop you.