42 Exam Practice – Final Exam Preparation

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This repository contains a collection of C programs and functions I implemented to practice for the 42 School final exam. Each file tackles exercises that were commonly seen, or similar variations of them.
They are only meant to strengthen skills in string manipulation, number handling, algorithmic problem-solving, and utility function implementation.

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📑 Table of Contents

1. Overview
2. Project Structure
3. Usage
4. Example
5. About 42
6. Contributing
7. License

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📌 Overview

The goal of this repository is to:

• Practice common C exercises that appear in 42 School exams.
• Review essential programming concepts such as strings, arrays, pointers, and algorithms.
• Improve speed and accuracy under time constraints.
• Provide a reference for other students preparing for similar challenges.

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📂 Project Structure

File / Function	Description
add_prime_sum	Calculates the sum of prime numbers up to a given number.
aff_a	Displays the first occurrence of the letter 'a'.
alt_case	Alternates the case of words in a string: first word lowercase, second uppercase, etc.; handles multiple spaces and tabs correctly.
do_op	Simple calculator: performs addition, subtraction, multiplication, division, and modulo.
epur_str	Removes extra spaces and tabs from a string.
even	Prints whether a number is even or odd.
expand_str	Expands spaces and tabs into exactly three spaces between words.
first_word	Displays the first word in a string.
ft_atoi	Converts a string to an integer.
ft_count_words	Counts the number of words in a string.
ft_interval	Creates and displays an array of integers between two values.
ft_itoa	Converts an integer to a string.
ft_range	Creates an array of integers in a given range.
ft_str_is_numeric	Checks if a string contains only digits.
ft_strcapitalize	Capitalizes the first letter of each word in a string.
ft_strlcat	Concatenates two strings with size limit.
ft_strncpy	Copies a string up to n characters.
ft_strrev	Reverses a string.
ft_strstr	Finds the first occurrence of a substring.
inter	Displays the intersection of two strings.
inter_space	Displays common characters of two strings, separated by spaces.
is_power_of_2	Checks if a number is a power of two.
is_separator	Checks if a character is a separator (space, tab, etc.).
last_word	Displays the last word in a string.
max	Returns the maximum value from an array of integers.
operations	Performs arithmetic operations based on arguments.
paramsum	Displays the number of program arguments.
repeat_alpha	Repeats each letter a number of times equal to its position in the alphabet.
rev_print	Reverses and prints a string.
rostring	Moves the first word of a string to the end.
rot_13	Encodes a string using ROT13.
rotone	Shifts each letter by one in the alphabet.
rstr_capitalizer	Capitalizes the last letter of each word and lowercases the rest.
search_and_replace	Replaces all occurrences of one character with another.
snake	Converts CamelCase to snake_case.
snake_to_camel	Converts snake_case to CamelCase.
strlen	Returns the length of a string.
ulstr	Switches lowercase letters to uppercase and vice versa.
union	Displays the union of characters from two strings.
wdmatch / wdmatch_	Checks if all characters of a word appear in another string in order.
zigzag	Prints a zigzag pattern based on given arguments.

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🛠 Usage

Each file is a standalone program.

• To compile and run an exercise:

gcc -Wall -Wextra -Werror ./program_name arguments

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Example for first_word.c:

gcc first_word.c -o first_word   

./a.out "Hello World" | cat -e

• Output:

Hello$

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🏫 About 42

42 is an innovative, tuition-free programming school with a unique peer-to-peer learning methodology.
It focuses on:

• Project-based learning
• Problem-solving without formal teachers
• Collaborative coding environments
• Strong emphasis on self-learning and creativity
• Preparing students for real-world software engineering challenges

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🤝 Contributing

Contributions are welcome!
If you’d like to improve or expand this repository:

1. Fork the repository
2. Create a new branch:

  git checkout -b feature-name

3. Make your changes and commit:

 git commit -m "Add feature description" 

4. Push to your branch:

  git push origin feature-name

5. Open a Pull Request

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📜 License

This project is licensed under the MIT License – you are free to use, modify, and distribute it for learning and practice.