Bitwise refers to a bitwise operation which operates on one or more bit patterns or binary numerals at the level of their individual bits.

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Code Chef problem COOKMACH

Firstly, I got the solution for this question in CodeChef, but I noticed one thing which still confuses me. This was the code which was accepted as correct. ...
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Reading bits from a stream from least to most significant

For a recent project I was in need of excessive bit manipulation. Specifically, I had to write to or read from a variable number of bits up from the least significant bit towards the most significant ...
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Performing add/delete/count operations on a list

Problem Statement (HackerRank) You have a list of integers, initially the list is empty. You have to process Q operations of three kinds: add s: Add integer s to your list, note ...
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542 views

Division without multiplication, addition or division

In context of preparing for a coding interview, I gave the division problem a go using Java. This is what I came up with. It's a little bit different to other solutions I've come across the interweb. ...
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8answers
657 views

String reversal, capitalize vowels, lowercase consonants

This was a portion of a skills test given to me by a company. The task was to write a method that takes a string, reverses it, and sets the vowels as capitals and consonants to lowercase. I was also ...
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3answers
157 views

Number of right cyclic shifts to give the biggest number

I am preparing to coding interview and I met this task today: You are given 30-bit unsigned integer N. A right cyclic shift of N by K bits is the result of performing a right cyclic shift of N by one ...
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3answers
288 views

Mockup in C of hardware implementation for multiplication of signed integers

I challenged myself to implement multiplication of signed integers using only +, -, ...
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1answer
46 views

Encoding variable-length quanties for MIDI

I was reading about the MIDI spec and I challenged myself to implement a function to convert an int32 to a variable length quantity uint32. I didn't look it up or ...
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107 views

Pixel bit-wise LSB extraction to byte array

I wrote the following code below to extract the least significant bit (LSB) of each pixel and store it into a byte[] array. I was wondering if Java has a more ...
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2answers
81 views

Verifying validity of Intel.hex file records

I have a class called FirmwareFile which represents and Intel HEX format file. The file is constructed with the name, build time and build date, at a later point ...
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1answer
129 views

Printing lines in a file, filtering by the first column

I am setting up a project which involves a lot of data analysis, each data point represented by a line in a large text file. In order to test for certain types of data, I added a tag to each line (It ...
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82 views

Bitstream reader

I have a program which reads and analyses MPEG-TS files. I've been using gperftools to identify hotspots and optimize them, and 45% of all samples at this point are in my main bitstream reader ...
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133 views

Fastest sum of absolute values of 32 differences

A long should be treated as a list of 32 unsigned numbers, each of them just two bit long. So 0x1234F... represents ...
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2answers
184 views

Gray codes addition — Take 2

For a while, I have tried to find ways (known or new) to do stuff with Gray codes. As some of you probably know, I already tried to implement an algorithm to add two Gray codes without having to ...
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2answers
171 views

Simple Binary Adder

The program adds two binary numbers in two' s complement ignoring the overflow for a constant size of bits. I am trying to generalize the program by taking input from the user in a single line without ...
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2answers
80 views

Given bit strings, perform a bitwise addition

I'm looking for code-review, optimizations and best practices. This code is a Java adaptation of code on geeksforgeeks.org. Please verify if space complexity is \$O(n)\$ where n is number of bits, and ...
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1answer
68 views
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1answer
191 views

Byte-to-binary conversion function

My implementation of a binary-to-bits converting function: ...
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2answers
256 views

Calculating holes on a Tetris grid quickly

I have created a Tetris AI which can play Tetris on its own given a set of rules. It places the next piece in every possible way on the board, and calculates which position that gives the fewest ...
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1answer
93 views

Network byte order to host byte order

While doing a little project involving sniffing packets, I found myself programming a cross platform network to host byte order and host to network byte order, this is my first time developing a ...
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828 views

Packing and unpacking two 32-bit integers into an unsigned 64-bit integer

Does this look good for combining/retrieving two 32 bit integers (a type and an index) into/from an unsigned 64 bit integer (a unique ID)? The point is to hide in the API the composition of the ...
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1answer
244 views

Optimizing code to find maximum XOR in Java

This problem is from HackerRank (not a competition, just for practice) Basically what you do is take in two integers as a range and then finding the maximum XOR from a pair of integers in that ...
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1answer
500 views

An Army of Ones

I've been practicing using recursion lately and thought this was a case where it would prove really useful, is this good use or is there some superior non-recursive way to go about it? Challenge: ...
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267 views

Bitwise operators for permissions

I'm trying to create a read-write-execute permissions system for items using user-group-world system. I already have the user/group system set up, just not the permissions. This is what I wrote: ...
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1answer
521 views

XOR of a list of a numbers

In preparing a solution for the CodeChef "Will India Win" challenge, I am trying to find out the xor of list of numbers. The first line of input contains the number of test cases, 1 ≤ T ≤ 106. ...
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1answer
95 views

Copy arbitrary number of bits at arbitrary offset from buffer to another buffer

I have just written a function copy_lowbits_off to copy any number of bits (not bytes) from a source buffer to a destination buffer. The function also supports ...
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1answer
78 views

Portable bitfields code generator

I am working on a project that involves quite a lot of instantiated objects, with tons of properties, most of which have only a few possible values, so the prospect of saving on memory is quite ...
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5answers
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Reversed Binary Numbers

Here is my code for "Reverse Binary Numbers" in C. Problem Your task will be to write a program for reversing numbers in binary. For instance, the binary representation of 13 is 1101, and ...
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Changing element visibility based on multiple checkbox states

I am writing a script in JavaScript & HTML and have some optimization problems. In the for, loop I check a variable named ...
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Bit stream input in Factor

My attempt at writing code to input values of arbitrary bitlength based on a bytearray in Factor. Any comments on the correctness or style would be appreciated. ...
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112 views

Speed optimization for transparent gradient blend algorithm

The following algorithm works correctly for the purposes that I need, which is to set the top side of an image with a transparent gradient blend. Any tips to optimize it for speed? ...
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Binary to decimal number converter

Here I am doing some exercises for my studies with Python. This is a binary to decimal number converter (currently restricted to that). These are the very first steps, so there is no error handling. ...
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2answers
225 views

Computing pairwise bitwise OR in a list of bit-strings

I am trying to solve this problem using Clojure: You are given a list of \$N\$ people who are attending ACM-ICPC World Finals. Each of them are either well versed in a topic or they are not. ...
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474 views

Gray codes addition

As some of you know, I have been working with Gray codes and am trying to design a good gray_code class in modern C++. I will end up posting several parts of the ...
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1answer
117 views

Implementing binary output to a file in C++11

I would like to have a class which supports outputting bits into a file. This is what I came up with but I fear there are many poor decisions. Should I inherit from a ...
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2answers
214 views

Embedded C# bitpacked arrays to low-level STM32F4 driver for GE G35 RGB LED Christmas tree light

I'm going to be opensourcing some code I'm working on. I don't need help with the code, I just want to make sure my code is readable and my comments make sense. I have a knack for the esoteric. ...
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1answer
407 views

Mostly portable 128 by 64 bit division

I wrote this out of curiosity. It is based on the theory behind Knuth's Algorithm D and is intended to emulate the behavior of the x86 div instruction (though the ...
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156 views

Saving bytes instead of objects to write smaller files

This question is about reducing the size of files saved to disk in an infinite world 2D mining game. I finally added code to my game to save and load distant chunks instead of keeping all of them ...
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Count bits that differ between integers X and Y

I'm trying to solve the following problem : You are given two integers, X and Y. Calculate the number of bits that will be changed in order to convert integer X to integer Y. Here is my ...
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1answer
266 views

Logical shift with signed numbers

I am going through the Coursera course The Hardware/Software Interface and because it has already ended, I would not be able to get any feedback on the code. The assignment is: LogicalShift: ...
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2answers
163 views

Lossy packing 32 bit integer to 16 bit

I am working on the lossy 16 bit representation for 32 bit integers that catches all 32 bit range with precision depending on absolute value. My idea is to store integer ...
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1answer
971 views

Steganography for images

For a school project I'm working on a small library to do steganography. I've just finished the first method of steganography and thought I'd get some feedback. This steganography method works by ...
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2answers
166 views

Array-like container for uints shorter than 8 bits (Rev 1)

This is a follow-up to Array-like container for uints shorter than 8 bits In short: The PackedBitfieldArray should be a kind of container for packed (unsigned) ...
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1answer
151 views

Array-like container for uints shorter than 8 bits

Follow-up: Array-like container for uints shorter than 8 bits (Rev 1) First of all: yes, I need this kind of array to generate data for a piece of hardware, and it must be stored and manipulated ...
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1k views

Diamond in the rough! Finding Gems in the rocks

Recently a question was asked that solved a hackerrank problem: Counting gems amongst the rocks The description of the challenge is: John has discovered various rocks. Each rock is composed of ...
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1answer
124 views

Bitwise operation to get the weekday name

The function days_name receive a val (string) corresponding to weekdays in hexadecimal. ...
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2answers
254 views

Emulating __uint128_t

I developed a lot of code locally with __uint128_t only to find out that it is not available on the target platform. I am now trying to write my own struct that ...
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1answer
443 views

Hexadecimal to RGB conversion

I am trying to convert hex to rgb, and rgb to hex. My current code doesn't seem optimal, and there is an issue with 0's in the hexadecimal. What do you think about the overall quality of this code? ...
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2answers
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Validating UTF-8 byte array

I'm writing a validator function that receives a byte[] and checks whether it represents a valid UTF-8 byte sequence, according to this table. Is my approach ...
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BitShift code compacting

I'm new to Java programming and am really enjoying it. I made a bitshift program, but I think it's too long. I expect the program to: Let users input the number and degree to be shifted Specify if ...