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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Josephus problem in C using linked list [on hold]

// why is temp2 not getting updated? It points to a[0]. ...
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0answers
10 views

How can I change my code using SIMD/AVX to calculate ranks in my page rank algorithm? [on hold]

I am writing a page rank program. I am writing a method for updating the rankings. I have successful got it working with nested for loops and also a threaded version. However I would like to instead ...
8
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0answers
24 views

Platformer in C

GitHub repo. main.c ...
5
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2answers
57 views

Thread synchronization with mutex

This program prints odd numbers by thread1 and even numbers by thread2 sequentially. Can this code be optimized or made more ...
5
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2answers
67 views

Fast CSV parser

I have written a CSV parser to read in 12609000 lines of CSV data. Each line has 16 fields of both string and double type data. The following code takes about 40 seconds to parse the data. I would ...
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0answers
30 views

Cuda C Matrix Compression

I am using Cuda to learn and implement a CSR matrix compression algorithm. What can I do better relating to C's best practices? main.c: ...
0
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0answers
36 views

Building a Stack with C structs

After reading the book from which this example is from I started using APIs like this ...
3
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2answers
49 views

Exercise 1-22 from K and R: line folding

I'm currently learning C with K&R, i'm right now in the exercise 1-22, but it's a little... hard to understand (at least for me). It says: Write a program to "fold" long input lines into two ...
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13 views
3
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1answer
78 views

POSIX arithmetic expansion

I understand that a shell should be able to perform arithmetic expansion. My shell can do it: $ echo $((1+2*3+4*5)) 27 My solution uses the lemon parser where I ...
3
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1answer
43 views

Two variants of a picture database initialization routine

I wonder which of the two snippets is better? In the second one, I extracted two short subroutines. On the one hand, extraction clearly separate the two tasks On the other hand, it induces 6 more ...
4
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1answer
51 views

Allocating a contiguous block of memory for an array

I try to work with a contiguous block of memory, to create an array (2D) whose SIZE is not known at compile time (before c99) so no variable-length arrays are involved here. I came up with the ...
0
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2answers
40 views

Two variants of a db_create_ressources(…) function

After reading noobs, I'm interested in possible way to improve readability of the following short snippet. a struct pictdb_file is a small file system containing ...
7
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4answers
351 views

Custom user input function

The program consists of 3 files: demo.c, mylib.c and mylib.h. The code is heavily commented. ...
0
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0answers
22 views

Recursive spinlock for C using ASM

My history of C/ASM locks here in codereview: Simple spinlock for C using ASM Simple spinlock for C using ASM, revision #1 (basis for this approach. If this one fails, then so will the one below.) ...
3
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0answers
34 views

Time Limit Exceeded with shortest path algorithm

The problem: SHPATH You are given a list of cities. Each direct connection between two cities has its transportation cost (an integer bigger than 0). The goal is to find the paths of ...
2
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1answer
30 views

Simple pool of threads which calculate the sum of a given number from the main process

I have to make a program which creates a number of threads that are waiting at the beginning, then the main process creates a doubly linked list where random numbers are put and then a signal tells ...
3
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1answer
47 views

Testing different implementations of malloc()

Can you help me verify my test result? I'm testing different malloc() implementations with a small program that allocates gigabytes many times: ...
3
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3answers
86 views

Counting the number of primes in C and C++11

I found this old piece of code that I wrote while I was learning C a while back: ...
2
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0answers
36 views

Simple spinlock for C using ASM, revision #1

Revision #1 for Simple spinlock for C using ASM The code: ...
4
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1answer
55 views

Simple spinlock for C using ASM

This is my second attempt to make simple lock using extended assembly. See http://stackoverflow.com/questions/37241553/locks-around-memory-manipulation-via-inline-assembly/37246263 The code: ...
1
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1answer
55 views

Structured, No Heap FizzBuzz

Here was my first, simple C fizzbuzz: ...
1
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0answers
27 views

Convert tri-gram of type wchar_t to an integer type

I am trying to convert a tri-gram containing 3 characters of type wchar_t to an integer type (an uint64_t at the present time). ...
1
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1answer
78 views

Reading from text files in C/C++ [closed]

I'm writing a program that has to check which are the two largest three digit numbers that are missing from a text file. I'm writing this in C++ and I'm trying to solve the mystery in a ...
3
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3answers
33 views

Array-based queue implementation using C

I wrote this header for generic use of a queue. The one thing I'm wondering is if I understood the usage of void*. I hope that if somebody teach me some conventions ...
3
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2answers
50 views

C - Improving (really) big number addition

I was lucky enough to stumble into this task during a job interview. I was gently guided to use string reversals and a few other things to speed up my process. I kept thinking that I wouldn't have ...
3
votes
1answer
60 views

Running shell commands in a pipeline

I'm writing a shell in C for Linux and BSD. My code was unreadable before but I did a rewrite and now it is much more readable. The purpose of the code is to create a command pipeline and execute it. ...
4
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1answer
39 views

Secure file system utility functions

For Khronos, I've had to develop these utility functions to help me deal with storing the .wav files. However, they could also be used in a variety of ...
4
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2answers
70 views

Recreating strstr in C

I'm trying to recreate strstr in c, my code works but I think it is too long, and it needs some improvement. ...
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2answers
344 views

The birth of my intelligent assistant: Khronos

I've done a lot of reworking to this main file recently, in regards to using a new speech recognition engine and integrating the last reviews suggestions. My question before is going to be phrased ...
2
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1answer
41 views

Median of 3 Quicksort in C

I'm trying to re-implement the C stdlib function qsort using a median of 3 quicksort. ...
5
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3answers
99 views

Simple file renamer in C

It's been some time since I wrote something in C. I am looking for some advices related to my code in terms of coding style, bad/wrong logic, optimization (performance) and good practices. The code ...
2
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1answer
51 views

Optimizations for bubble sort

The code performs bubble sort on the basis if any swaps has been performed in the iteration. I made it sort of independent of number of iterations as in any conventional bubble sorting code. I went ...
3
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1answer
26 views

AES Wrap function

This code is supposed to implement RFC 3394 which also described in this PDF at page 11. Are there any weak places or formatting issues in attached source? Or maybe some places are not explicit ...
3
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1answer
66 views

Small Poker program in C

I made a small Poker program with C but I believe I could've written it better. Full source on bitbucket.org ...
4
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1answer
41 views

Automake for an S/KEY implementation

I've been tasked with giving a legacy codebase some love. The actual code is written in C, but is not very relevant aside from the #includes each file makes. No, ...
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2answers
48 views

Rewrite 12 consecutive ints based on bizarre logic

Despite looking terribly ugly, it is pretty interesting due to some specific connections to cellular automata theory. I'm looking for ways of simplifying it further. This program takes 2.7 seconds to ...
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1answer
42 views

Creating a struct

Mat told me to create a struct create a struct for the individual commands and arguments. It should have something like the "executable" name, number of args and arg list. Create a few ...
1
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1answer
50 views

Makefile and translating it to Cmake

My makefile looks like this and I translated it to cmake. ...
0
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0answers
23 views

Prefetch in ARMv7

I have to implement Khatri Rao product between 2 matrices in C. Mathematically this is a column major access of data and I can not change that. But if I use preload ( PLD instruction in ARMv7 ) to ...
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1answer
52 views

Printing a prime normalized sequence

The program below generates a prime normalised sequence. So, what happens is this: It asks you to provide a number within a range. Program then calculates a factor which is inverse of product of all ...
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3answers
42 views

C single-linked list with remove

Can you please point out any problems with this C forward list with remove node functionality? I believe this can be way simpler ( removeNode function ) but I ...
0
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1answer
24 views

C function for copying array into matrix

I want a matrix that can grow dynamically and build up a structure in RAM as input arrives from standard input och terminal (shell). First I tried with a matrix like ...
3
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2answers
317 views

C dynamic array implementation using preprocessor

I have implemented a generic dynamic array implementation using defines. As I am new to C, I am not sure whether the code has any flaws. The code is as follows, ...
4
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1answer
51 views

Program to convert binary to hex

I wrote this program to convert binary to hex, it ignores other characters between the binary digits. I would like to receive any recommendations on how to improve it. ...
2
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3answers
54 views

Parabola calculations - follow-up

Previous question After applying the suggestions, I wanted to revise the question with the new code because I don't think this is good enough. ...
2
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1answer
74 views

Testing a shell command interpretor

I've written tests that use Bash for testing a custom shell. I think the tests work but I'm sure you know better because this is my first test I write this way. ...
2
votes
1answer
46 views

Find the contiguous subarray within an array (containing at least one number) which has the largest sum

Interview Q: Find the contiguous subarray within an array (containing at least one number) which has the largest sum. For example: Given the array [-2,1,-3,4,-1,2,1,-5,4], the contiguous subarray ...
0
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1answer
62 views

Shell command line program

I have refactored a for loop into a function. I'm still a beginner at using C utility functions such as strtok, ...
4
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1answer
57 views

Bubble Sort in C

I am trying to learn C coming from Python. Below is an implementation of bubble sort, slightly optimized. Any advice on best practices, readability, use of macros, and edge cases would be greatly ...