HAW Coding Challenge 2022

🏆💻 Welcome to the HAW Coding Challenge 2022!

This repository contains the exercises for the HAW Coding Challenge 2022.

Each day a new exercise will be published. Do your best to complete the exercise and follow the instructions.

At the end of the day, the best solution will be selected and the winner will be announced. ...wait, there is no prize. 🤔

Anyway, you can learn a lot by doing this challenge.

And it's Eger-approved! 🤓

And at the end of each day a solution together with a detailed explanation video/tutorial will be published to the folder of the exercise.

Questions

If you have questions, feel free to ask them in the group chat or hit me up on WhatsApp.

This challenge is open to everyone. You can participate individually or in a team.

Happy coding!

And remember: Don't Panic!

How to participate

Go into the folder of the exercise and read the README.md file (it is automatically shown on GitHub when you click on the folder above).

The README.md file contains the instructions for the exercise.

The main.c file contains the template code for the exercise. You MUST NOT modify the template code.

Download or copy/paste the template code into your IDE and start coding.

Exercises

Click on the exercise to see the instructions.

New exercises will be published (almost) every day.

Exercise 0 - Hello REE!

Exercise 1 - [Hu]rraaaaaays Part I

Exercise 2 - Ho ho ho! 🎄⛄️

Exercise 3 - Brrrrr!!! It's cold outside! 🥶 (Out now!)

Exercise 4 (Coming soon!)

Exercise 5 (Coming soon!)

Template Code

Each exercise has a template code.

The template code is a starting point for the exercise.

The template code MUST NOT be modified.

The predefined parameter, variables, and function names MAY NOT be modified. You may also NOT add/remove parameters

Parameters

// Template code:
int print_int_array(int *arr, size_t arr_len)
{
    // ...

    return 0;
}

// DO NOT MODIFY LIKE THIS:
// i.e., changed parameter name
//       change parameter type
int print_int_array(int *array, int count)
{
    // ...

    return 0;
}

Headers & Libraries

You may use any of the given libraries. Unless explicitly stated you MAY NOT include any other libraries.

// Template code:
#include <stdio.h>
#include <stdlib.h>

int main(int argc, char const *argv[])
{
    // compute string length
    // size_t str_len = ...

    return 0;
}

// DO NOT MODIFY LIKE THIS:
// i.e., added library
#include <stdio.h>
#include <stdlib.h>
#include <string.h>    // <-- DO NOT ADD THIS

int main(int argc, char const *argv[])
{
    // compute string length
    size_t str_len = strlen("Hello World");    // <-- TO USE strlen() HERE

    return 0;
}

Important Requirements/Limitations

The code should respect certain requirements and limitations to be considered a "correct" solution to the problem.

The code should be OS-independent. It HAS to be compatible with UNIX. i.e., Ubuntu, Linux, macOS, etc.

OS-dependent headers

This means that the following libraries should not be used:

// Only on Windows
#include <windows.h>

// Only on UNIX
#include <unistd.h>
#include <pthreads.h>

or be integrated via OS-dependent code with the preprocessor:

#ifdef _WIN32
    // Windows code
    #include <windows.h>
#else
    // UNIX code
    #include <unistd.h>
    #include <pthreads.h>
#endif

Clear screen via system()

Another example is the use of the system() function. The passed parameter is OS-dependent. Therefore, it should be implemented via a preprocessor directive.

#ifdef _WIN32
// Windows implementation
void clear_screen(void)
{
    system("cls");

    return;
}
#else
// UNIX implementation
void clear_screen(void)
{
    system("clear");

    return;
}
#endif

// Call it as usual
int main(int argc, char const *argv[])
{
    clear_screen();

    return 0;
}

Console I/O

All stdin/stdout (standard in/standard out) is only allowed in main() or dedicated print functions.

i.e., printf(), fprintf(), scanf(), etc.

For example: print_int_array().

Keep your code clean and make sure that it is obvious where the input/output is happening.

File I/O

All file I/O is only allowed in dedicated file I/O functions.

i.e., fopen(), fclose(), fread(), fwrite(), etc.

For example: read_file(), write_file().

Keep your code clean and make sure that it is obvious where the file I/O is happening.

Error handling

The following error checking should be done:

• NULL ptr checking
• Value conversion/casting (e.g., double -> int)
• Memory leaks (e.g., free memory, etc.)
• User input (e.g., scanf, etc.)
• File I/O (e.g., file exists, file is readable, etc.)
• Command line arguments (e.g., argc, argv, etc.)

Errors should be handle in one of two ways:

• exit program, if not executable otherwise

  exit(EXIT_FAILURE);
  
  // or
  
  exit(1);

• return a safe value for continued execution if it makes sense

  return 0;