Rank 02 Level 0 Cram Plan 1 - kevshouse/exam_quest GitHub Wiki
Analysis of Level 0 Model Questions for 42 School Common Core Rank02 Exam Overview The provided questions focus on fundamental C programming skills: string manipulation, character processing, pointer operations, and basic logic. You are limited in library functions (often only write is allowed), so manual implementation is required. Your revision strategy—mastering helper functions and then building more complex solutions from them—is well suited to these problems.
Key Topics and Helper Functions
- String Manipulation Many assignments require traversing or modifying strings. Core helper functions to practice:
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ft_strlen: Returns the length of a string.
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ft_strcpy: Copies one string to another.
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ft_putstr: Prints a string using write.
Mastering these will help you build more complex logic, such as reversing strings or searching/replacing characters.
- Character Analysis and Manipulation Several tasks require checking or transforming characters:
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Check for alphabetic characters: Useful for repeat_alpha, ulstr, rotone, rot_13.
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Check for whitespace: Needed for first_word.
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Case conversion: For ulstr (swap case).
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Alphabetical index calculation: For repeat_alpha (e.g., 'b' is 2).
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Pointer Operations ft_swap: Swapping integers via pointers is a classic pointer manipulation exercise.
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Output All output must be done via write, so practice writing single characters and strings without printf.
Assignment Breakdown and Revision Strategies
first_word
Key skills: Skip leading whitespace, identify word boundaries, output substring.
Helpers: is_space(char), ft_putstr, ft_strlen.
Strategy: Practice writing a function to skip spaces/tabs, then print until next space/tab or end.
fizzbuzz
Key skills: Looping, conditional logic, integer to string conversion.
Helpers: ft_putnbr (write number as string), is_divisible_by(int, int).
Strategy: Write a helper to output numbers, then build fizzbuzz logic.
ft_putstr
Key skills: String traversal, output.
Helpers: None needed; basic loop and write.
Strategy: Practice writing a loop to output each character.
ft_strcpy
Key skills: Copying strings, pointer manipulation.
Helpers: None needed.
Strategy: Write a loop copying each character until '\0'.
ft_strlen
Key skills: Counting characters in a string.
Helpers: None needed.
Strategy: Loop until '\0', incrementing a counter.
ft_swap
Key skills: Swapping values via pointers.
Helpers: None needed.
Strategy: Use a temp variable to swap *a and *b.
repeat_alpha
Key skills: Character analysis, repetition, output.
Helpers: alpha_index(char), is_alpha(char).
Strategy: For each character, if alpha, repeat it (index) times; else, print once.
rev_print
Key skills: String traversal, reverse output.
Helpers: ft_strlen.
Strategy: Find string length, then output from end to start.
rotone
Key skills: Character transformation, output.
Helpers: is_alpha(char), is_upper(char), is_lower(char).
Strategy: For each letter, increment by one (wrap z→a, Z→A).
rot_13
Key skills: Character transformation, output.
Helpers: is_alpha(char), is_upper(char), is_lower(char).
Strategy: For each letter, shift by 13 (wrap as needed).
search_and_replace Key skills: String traversal, comparison, replacement.
**Helpers: ** None needed.
Strategy: For each character, if it matches the search char, output the replace char.
ulstr Key skills: Case swapping, output.
Helpers: is_upper(char), is_lower(char), to_upper(char), to_lower(char).
Strategy: For each letter, swap case; else, print as is.
Recommended Revision Order
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Basic String Functions
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ft_strlen
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ft_strcpy
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ft_putstr
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Character Helpers
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is_alpha, is_upper, is_lower, to_upper, to_lower, is_space
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Pointer Basics
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ft_swap
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Output Helpers
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ft_putnbr (for fizzbuzz, if needed)
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Build Up to More Complex Programs
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- rev_print (uses ft_strlen)
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- first_word (uses is_space, ft_putstr)
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- repeat_alpha (uses is_alpha, alpha_index)
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- rotone, rot_13 (use is_alpha, is_upper/lower)
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- search_and_replace (string traversal, comparison)
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- ulstr (case conversion)
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- fizzbuzz (looping, output, conditional logic)
General Revision Tips
Avoid malloc unless required: Most problems do not require dynamic allocation; use stack variables and pointer arithmetic.
Practice writing to output using write:
Since printf is not allowed, get comfortable with write for both single characters and strings.
Test edge cases:
Empty strings, no arguments, multiple arguments, special characters.
Reuse helpers:
Build a small library of helper functions (e.g., is_alpha, is_space) and use them across exercises.
Understand argument handling:
Many programs require checking argc for the correct number of arguments.
Sample Helper Functions (Pseudocode)
int ft_strlen(char *str) {
int i = 0;
while (str[i])
i++;
return i;
}
void ft_putstr(char *str) {
int i = 0;
while (str[i])
write(1, &str[i++], 1);
}
int is_alpha(char c) {
return ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'));
}
int alpha_index(char c) {
if (c >= 'a' && c <= 'z')
return c - 'a' + 1;
if (c >= 'A' && c <= 'Z')
return c - 'A' + 1;
return 0;
}
Conclusion
**Focus **on mastering small, reusable helper functions for string and character manipulation. Build your solutions incrementally, testing each helper before integrating them into larger programs. This approach aligns perfectly with the style of the 42 School exam and will help you efficiently solve the model questions in paste.txt.