Questions tagged [c]
C is a general-purpose computer programming language used for operating systems, games, and other high performance work and is clearly distinct from C++. It was developed in 1972 by Dennis Ritchie for use with the Unix operating system.
3,913
questions
2
votes
1
answer
36
views
Advent of Code 2023 day 1: Trebuchet (Part 1 and 2)
Part 1:
The task involves analyzing a calibration document containing lines of text. Each line represents a calibration value that needs to be recovered by extracting the first and last digits and ...
- 2,364
-2
votes
0
answers
28
views
Im new to Programming and my code doesnt work [closed]
This program should output the smallest array index of the most common letter in the string and it works for some inputs but for example "zzz" and "AAA" outputs 1 instead of 0 :(
<...
- 1
3
votes
1
answer
81
views
Simple hash table written in C with REPL
This is a simple hash table I've written in C. It is a closed-addressing hash table with TABLE_SIZE number of buckets. The hash ...
- 223
1
vote
1
answer
80
views
Simple text file encryption and decryption
Short introduction; recently I've completed a basic course on C but other than that I have no programming experience and I am a total beginner.
As a practice project and to practice reading from and ...
- 13
13
votes
7
answers
2k
views
Optimise a program that outputs the earliest date
I am attempting to solve Question 10 of Chapter 6 of the C programming: A modern approach book.
The question asks to write a program that determines the earliest date from a sequence of user-inputted ...
- 131
4
votes
3
answers
552
views
char* to integer implementation (atoi with saturation to INT_MIN or INT_MAX on overflow)
I am learning C. As a task, I need to write a get_int function that will convert a char* to ...
- 51
4
votes
2
answers
837
views
C Bit Utility Functions: Popcount, Trailing Zeros Count, Reverse All Bits
Here are some utility bitwise functions for 64 bit integers. I have independently derived inv64 (inverse all bits) and pcnt64 (...
- 823
0
votes
1
answer
71
views
C Element based FiFo-Buffer Implementation
Hey,
i just finished work on a Element based FiFo Buffer in C.
Layout of this question:
Intro
.h File
.c File
Usage Example
Intended Use-cases
Question
.h File
...
16
votes
7
answers
3k
views
Image Processing Application in C
I'm making a image processing application in c from scratch using P6 ppm images, I want some input on my code before I start adding more features to prevent it from falling apart if it's not well ...
- 163
0
votes
3
answers
68
views
another Merge Sort
I've tried to implement merge sort in c with varying degrees of success, one was correctly sorting the array but leaking memory, one was neither sorting the array and leaking memory.
The following was ...
- 103
7
votes
1
answer
685
views
Boolean conversion for fscanf()
In answering How to do file I/O with bool in C?, I made a helper function that used fgetc() calls to substitute the missing ...
- 30.4k
11
votes
4
answers
2k
views
Simple Key Value Database using C
I was recently doing an assignment for a job interview, which asked to create a simple key value database with 4 command line operations:
create key value: Adds a key value pair/updates an existing ...
- 111
1
vote
2
answers
1k
views
Calling fgets() twice
I am a beginner. I have really struggled with fgets() when using the function twice. I am on Windows with VS Code and C++ extension. My test program is working, but it is IMHO lengthy and complicated ...
- 29
3
votes
1
answer
136
views
Filter: BMP Image Filtering Tool - follow-up
This is a follow-up of this quesiton: Filter: BMP Image Filtering Tool
Changes:
Added comments where necessary.
Added checks for integer overflow.
Added support for input and output redirection.
...
- 2,364
1
vote
0
answers
63
views
binary semaphores implementation pthread
Can someone see if have not made some stupid mistakes in the binary semaphore implementation? I know that some more checks have to be added but I have eventually lost the initial idea in the details.
<...
- 170
4
votes
1
answer
229
views
200 line Brainfuck Interpreter
I wrote a simple brainfuck interpreter in C99. Coming from a background of C++ made the task easier, but still there is some stuff I had to get used too. The program accepts a path to a brainfuck file ...
0
votes
2
answers
126
views
5
votes
1
answer
383
views
Simple malloc and free implementation
I am trying to implement a simple malloc and free. The buffer is a char array.
Each chunk's address is calculated using the size of the previous chunk.
...
- 51
1
vote
1
answer
77
views
Poker Hand Evaluation evaluation
Several days ago, a question on this topic was posted to SO. The problem turned out to be the OP's test cases did not reveal a deficiency in the code. This challenge caught my attention. Writing the ...
- 183
1
vote
2
answers
63
views
bucketsort with multiprocessing
I want to compare the procedure time for each number of process. I made 5000000 numbers in input.txt in random order. I read it and do bucket sorting with ...
- 11
6
votes
4
answers
966
views
Filter: BMP Image Filtering Tool
Filter is a C program that allows you to apply filters to BMP images.
Usage:
Usage: filter [OPTIONS] <infile> <outfile>
Review Goals:
General coding ...
- 2,364
4
votes
2
answers
2k
views
Linked list and array list performance comparison in C
After watching Stroustrup's presentation on performance comparison between vectors and linked lists (https://youtu.be/YQs6IC-vgmo?si=9r5wXqnwkmN29xqn), I've decided it would be a good problem to get a ...
- 93
5
votes
2
answers
314
views
Wordle50 - A Command-Line Word Game
"Wordle50" is a command-line-based adaptation of the popular Wordle daily word game. In this word-guessing game, players aim to decipher a randomly selected word with lengths varying from 5 ...
- 2,364
17
votes
5
answers
5k
views
malloc() and free() implementation
I'm looking for a code review of my custom memory allocation library (written for educational purposes), which includes malloc(), ...
- 2,364
5
votes
3
answers
769
views
Implementation of recursive `ls` utility
Recently I wrote my own implementation of a utility for recursive output of the directories' contents, kind of similar to the ls Linux utility with the ...
- 215
3
votes
1
answer
94
views
HTTP Request-Line parser
I am trying to write an HTTP/1.0 (RFC 1945) parser in C, so I started with the Request-Line. Ideally, the parser should return one of the three:
The request is valid.
The request is malformed, but ...
- 131
4
votes
1
answer
332
views
Porting xoroshiro1024** from C to C#, and seeding it
I require a PRNG which:
Has repeatable results from a given state.
Is both seeded from and has a state containing a sufficiently large amount of data (somewhere in the region of 700 bits or more) to ...
- 141
1
vote
2
answers
122
views
Ackermann function iterative-recursive form in C
I am trying to write the Ackermann function iterative in m and recursive in n. I got to this point where the code I provided below work for all values below Ack(5,0) but it overflows after this value. ...
- 11
3
votes
1
answer
106
views
C-style double expression parser
The purpose of this code is to parse any expression as could appear in C that involves doubles or functions that involve only doubles.
I have written parsers before:
Command line calculator in C
...
- 823
5
votes
1
answer
86
views
Small HTTP client/SDK created using libcurl in C language
I created a SDK in C for my Rust project (a key value store in Rust). It should give access to the HTTP routes in a simple manner. (I never worked with C outside of university.)
I used:
...
- 153
6
votes
3
answers
631
views
1
vote
2
answers
90
views
Rate my Makefile
Here's the Makefile I've built up over the last two years which I use as a template (most often verbatim apart from target name(s)). It's meant to be used for C ...
- 133
1
vote
5
answers
246
views
Sum of bitwise XOR of each subarray weighted by length
here is the problem statement
You are given an array a of length n consisting of non-negative integers.
You have to calculate the value of \$\sum_{l=1}^n \sum_{r=l}^n f(l,r)\cdot (r - l + 1)\$ where \...
2
votes
2
answers
142
views
Checking a mastermind answer as fast as possible
This is not your typical mastermind question, I am not trying to find the right answer. Merely to check the answer and provide a result as fast as possible. The function signature cannot be changed, ...
- 133
1
vote
2
answers
223
views
Iterating the octree while keeping track of the positive neighboring nodes
Review context can be found here: 32x32x32 Units Octree With 15-Bit Voxels: Second Edition
The above question and the self answer include information such as the definition of the ...
- 823
4
votes
2
answers
104
views
implementation of Conway's game of life in C for ansi terminals
I've been learning C for some quite time now and wanted to test my skills by implementing the game of life in C. Please give me a general review, and include the style. Is code like that of function ...
- 143
3
votes
2
answers
221
views
32x32x32 Units Octree With 15-Bit Voxels: Second Edition
A while back I made an octree system that stores 15-bit voxel in a 32x32x32 voxel octree: 32x32x32 units octree, that supports 15-bit data units
I have since improved upon this system. The new octree ...
- 823
5
votes
2
answers
512
views
Stopwatch program written in C, using Pico W
I've a raspberry Pico W and developed a simple stopwatch program in C. I configured GPIO pin 15 as an input and enabled the internal pull-up resistor. If the state is high, I will start the timer and ...
- 53
9
votes
2
answers
119
views
Hangman game in C
I am a beginner who wrote this simple Hangman game in C for fun and to practice programming. I am looking for advice on optimizing this code and making it adhere to best practices. Are there too many ...
- 103
2
votes
4
answers
248
views
Generic type data storage
We have a module which can be used by user to store and load value of variables. Every variable has an index associated with it (in the shown code cample this is ommitted and index is instead the data ...
- 83
0
votes
2
answers
102
views
Improving performance of mandelbrot set calculation
I am making a hobby OS, and I thought about adding a command for interactively rendering the Mandelbrot set. The "interactive" part is not really important, but I wanted to check if the ...
- 111
0
votes
0
answers
45
views
Finding the pivot point in a rotated array which has been shifted from kth element
I'm trying to solve the following problem:
Joker has a deck of n cards, each with a value written on it. The cards are arranged in ascending order from top to bottom. Joker's master performs a hidden ...
- 212
0
votes
0
answers
42
views
C idiom for multi-layer buffered input with processing
I'm writing a bit-level IO code that handles endianness conversion for the short/uint16_t type in the IO subroutines. Here's the code:
...
- 310
5
votes
3
answers
103
views
Download stock data from YFinance
As a project to get more familiar with curl, I decided to write a program that downloads stock data from Yahoo Finance, and does arbitrary analysis on that data. I would like to receive any critiques ...
- 9,989
2
votes
1
answer
61
views
K&R excercise 1-21 Write a program entab that replaces strings of blanks by the minimum number of tabs and blanks to achieve the same spacing
Exercise 1-21. Write a program entab that replaces strings of blanks
by the minimum number of tabs and blanks to achieve the same spacing.
Use the same tab stops as for detab. When either a tab or a ...
- 143
2
votes
1
answer
75
views
K&R "The C Programming Language" exercise 1-13: histograms
Exercise 1-13. Write a program to print a histogram of the lengths of
words in its input. It is easy to draw the histogram with the bars
horizontal; a vertical orientation is more challenging.
The ...
- 143
4
votes
1
answer
225
views
3
votes
1
answer
78
views
Arm GPIO driver
I'm new to bare-metal programming. I'm currently developing some drivers for my first project.
This is a simple GPIO driver. I tested it and it's working fine.
What do you guys think of it, and how ...
9
votes
3
answers
1k
views
C function to read only numeric values
I'm learning C and as exercise I'm trying to implement a custom function to parse a input from user and return successfully only if the input is a number.
These are my files, how could I improve it?
...
- 93
1
vote
1
answer
74
views
CS50 Week 2: Converting vowels to numbers and outputting new string
Problem: User inputs a word or phrase as command-line argument and a new word is printed with some vowels replaced by numbers.
Question: How do I improve my code design and style? Is it possible to ...
