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.
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Exercise to create an insertString function to linked-list. Seems too simple. Am I missing something?
Working from 'Programming in C' by Kochan. I'm on an exercise in the chapter 'Pointers'.
This was the exercise:
'Write a function called insertEntry() to inset a ...
13
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4answers
964 views
Printing the PID of a program immediately before it runs
I need to know (for monitoring purposes) the PID of a program immediately before I start it. There could be multiple of the same program launched at the same time, so monitoring ...
2
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2answers
27 views
Counting the number of lines in a file
I'm easing back into C after several months of using Python and Matlab. Can anyone give me some pointers on how to improve my code's efficiency and readability?
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1answer
108 views
Function to find a substring within a string [on hold]
I've just completed an exercise in which I had to create a program that searches for a string within another bigger string.
If the substring exists then it is outputted to confirm and the starting ...
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2answers
1k views
Taking arbitrary length input in C
Instead of having to use something like char buf[100500] and hope that no possible user input could be longer than 100500 bytes, I decided to make the following ...
6
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3answers
99 views
Revised - Game of Fifteen
This is a revised version of a previous post. I attempted to address each aspect of the feedback provided. The key changes are as follows:
Replace the deprecated ...
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0answers
17 views
Testing a C library without access to internals [on hold]
I wrote a simple C library which generates OAuth authorization headers. It exposes a few methods for setting the parameters that are required from the user, such as the url, token, http method, etc; ...
4
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3answers
41 views
C Threadsafe Priority Queue O(log n) push, O(1) pop
I wrote this for an A* implementation:
(pqueue.c)
...
7
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2answers
119 views
Game of Fifteen - A Sliding Puzzle Game
Update: I addressed the changes and created an updated post.
I'm reviewing C by working through the edX CS50 problem sets. This task was to implement Game of Fifteen aka 15 Puzzle. Project details ...
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2answers
73 views
Designing stack and queue from scratch in C
As a beginner and curious guy I'm interested in implementing data structures and algorithms from scratch. Here's my implementation of Stack and Queue, the most fundamental data structures.
Are ...
7
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1answer
32 views
Implementing checksum add without carry in C
I need to write a function in C which performs a checksum using the rule "add without carry". As I understand it, the "add without carry" concept is equivalent to the bitxor operator and given that ...
0
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1answer
12 views
Efficient ways of looking for start-key and processing data
This question is a follow up from my previous question.
I am working with some wireless communication in Arduino.
979797 is the address of the transmitter. I have written the following code to ...
2
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0answers
44 views
Better Brainfuck Interpreter in C
A little over a week ago I posted my basic brainfuck interpreter here. I have since improved the interpreter on all suggested points except two minor details. (reporting the position of parsing error, ...
2
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2answers
46 views
AVL tree insertion and deletion of nodes in C. 2.0
I asked a question yesterday, based on the answers to that question and some personal insights I was able to update the original code. which I am posting here to get reviewed. I also thought about ...
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2answers
137 views
AVL tree insertion and deletion of nodes in C
This is my implementation of AVL tree, it works fine. is there any thing that can be improved about addition and deletion procedures specifically when deleting the root,
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2
votes
2answers
33 views
Dividing a long (arbitrary-precision) number by an integer
As part of a (slightly) larger program, I needed to write a function that could take an arbitrarily large number and divide it by a small number. In this program, I will be dividing this number ...
6
votes
3answers
501 views
Sort a binary file without loading it into memory or using a temporary file
I had a silly assignment:
You are given a binary file FLOATS.DAT of unknown length, type float
data has been written in it. Write a program which sorts the ...
8
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1answer
60 views
Process bytes and check for start key
I am working with some wireless communication in Arduino. My data will be wirelessly received like so:
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97
97
...
...
979797 is the address of the transmitter. ...
4
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1answer
107 views
New malloc implementation
I've written a new malloc implementation similar to dlmalloc and was hoping for feedback on it.
The goals for this library are:
...
6
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2answers
45 views
Reading a line ending with a newline character from a file descriptor
I'm implementing a function that behaves like getline() which reads a line from file descriptor and returns the results without ...
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0answers
23 views
Generic Pairing Heap Performance
I have made a generic pairing heap library in C. Pairing heaps are one of the several heap variants with better asymptotic running times than standard binary heaps (others include Fibonacci heaps and ...
0
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1answer
40 views
Parse 2D matrix, 2 versions
I'm writing a little C program that computes matrices (for learning purpose). The matrix is fed through arguments in the following form : "{{43,543.324,34},{43,432,87}}"
The user doesn't give the ...
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1answer
42 views
1
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1answer
40 views
7
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3answers
400 views
Designing a binary tree structure from scratch in C
I'm a beginner and self learning programming students. While learning binary tree data types, for the sake of understanding graph theory and other interesting programming problems, I've writen the ...
7
votes
2answers
130 views
Tensor product formula
Recently, I wanted to use C to implement the following formula:
$$\mathbf S(u,v)=\sum_{r=i-p}^{i}\sum_{s=j-q}^{j}N_{r,p}(u)N_{s,q}(v)\mathbf P_{r,s}$$
Namely,
$$
\left(N_{i-p,p}(u),\cdots,N_{i,p}(...
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8answers
6k views
C program that reverses a string
As practice with the (ever so painful) C Strings I wrote a string reversal program. I am new to C, so I wanted to make sure that I am not using bad coding practices. It runs just fine (at least with ...
5
votes
2answers
418 views
Basic Brainfuck Interpreter in C
I have written a small Brainfuck interpreter in C. More recent version hosted here.
I have found it very hard to test my interpreter because writing a program in Brainfuck is somewhat hard (or at ...
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1answer
41 views
Multi Producer - Single Consumer
I have written multi producer single consumer code with bounded buffer. Please review the code for any improvements or mistakes.
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0answers
22 views
Parallel Hillis-Steele Scan using CUDA
I'm learning CUDA (and C to some extent), and one of the algorithms that I am learning is the Hillis-Steele scan algorithm. I wrote a program that performs a simple scan with adding.
After seeding ...
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3answers
120 views
Converting a decimal into a fraction
I have written a small program that converts a decimal number into a reduced fraction representation. I also designed this little program to be fairly robust, so that it can give the correct output ...
3
votes
2answers
96 views
Count the number of ways to obtain a sum, with consecutivity restriction
A cricketer can score 1, 2, 4 or 6 in a ball. Find in how many ways the player can score a total of "n" runs without hitting 3 consecutive boundaries. Note: Scoring 4 or 6 is considered as a boundary. ...
8
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1answer
71 views
Simple Lotto Game
I have developed a Lotto Game in C for my Assignment, it allows a user to enter one of the 6 menu options.
From the menu the user would be able to view the numbers they have chosen, another option ...
5
votes
0answers
32 views
Positioning a file pointer with MPI I/O
This toy code uses MPI I/O to read from a binary file.
It goes through reading:
an ASCII header
the first 10 doubles from an array of 100 ...
3
votes
1answer
72 views
3
votes
1answer
43 views
Pretty print a 2D matrix in C (numpy style)
Works for any 2D matrix represented by a 1D array. Comments and criticism welcome. Also wondering whether the code can be made shorter. It's really messy right now.
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1answer
81 views
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39 views
'Terminated due to time out'. Need help in optimising my code
I am trying to implement dictionary. I would appreciate if you find the flaws in my code rather than changing whole logic.
Attaching the link of Problem
https://www.hackerrank.com/challenges/30-...
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votes
2answers
100 views
Multi threaded text-based tetris game
I have decided to make a game of text-based Tetris in C.
At first I had no idea how to start so I settled for threads.
Each thread moves its own piece down the grid and all the main thread does is ...
6
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3answers
67 views
Four versions of a database-creation function with different error handling
I'm starting a new, small C project and would like to have the safest, cleanest and shortest error handling code possible.
Here is a comparison of different ways to handle errors in the same C ...
4
votes
2answers
38 views
Error-checking macro to jump to specified label given a failing statement
I'm starting a new C projet and I want to have the cleanest and shortest error checking code possible.
To that aim, I often use two things :
functions return 0,...
6
votes
1answer
111 views
C the sum of primes
The challenge is to calculate the sum of the first 1000 primes. The code applies a sieve thanks to past answer, here, and works but I wonder about the flexibility of this solution.
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2answers
148 views
How do I write my multithreading code correctly so that it is faster than a single thread?
I have the following code that I am trying to optimize. I am running it on a Linux machine with 24 cores. I thought I could use multithreading to make it faster, but it's somehow making it way slower ...
3
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1answer
133 views
A small generic array in C
The generic arrays in C I found on the net used either of these methods:
The preprocesser with #define and #include (a lot of ...
4
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1answer
42 views
Polymorphic pointers-to-functions whose parameters are void pointers as arguments in C
My question is about this sort of table that's simplified here. Often, I find myself putting this element, (int (*)(const void *, const void *))&strcmp for <...
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2answers
153 views
Dijkstra's algorithm for computing the GCD of two integers, translated from C to x86 assembly
This is the x86 version of a C file assignment (I have included both). We were to convert the C code to assembly. I am rather new at assembly and would really appreciate suggestions and help for ...
1
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4answers
143 views
Program to display array elements in the ascending order of number of factors each element has
Input:
1000 23 100 26 32
Output:
23 26 32 100 1000
Since 23 has '2' factors and 26 has '4' factors and 32 has '6' ...
8
votes
3answers
216 views
Check if 2 rectangles fit in another one, given their length and height
I was very intrigued with the manner to solve this problem. The program needs to know if 2 rectangles fit in another one, considering the lines of the 2 rectangles are always parallel to the other one'...
1
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0answers
29 views
Tab completion for custom shell
The purpose of the code is to enable tab completion for a custom shell I'm writing. The target OSes are Linux and OpenBSD. I had to make a conditional include that I hope is correct:
...
14
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9answers
2k views
Given three numbers, find the second greatest of them
I've just coded this for my country's programming Olympiad. I want to know if this method is a good approach in terms of readability and performance. I would also like to know how to improve it.
Note:...
