# Questions tagged [bitwise]

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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### Representing Tic-Tac-Toe using a binary BitBoard

So I have been learning more about binary numbers lately, particularly in related to describing a gamestate. While perhaps chess is the most natural candidate I wanted to start of with something ...
2answers
53 views

### Move an unaligned bit-addressed range into another bitmap

Context I have an array of maximum-fixed-size, size, containers of items; these items are either pointers to objects or an index of the same array, (but no loops.) ...
2answers
61 views

### Generate mask for non zero (or inverse) nibbles in integer

Apologies for the cryptic title, but the problem really is rather simple. I have a 64 bit integer which I interpret as 16 4 bit nibbles, or a nibble array if you wish, and I needed generate a mask ...
3answers
67 views

### How to refactor a method with many prameters that sets a bit array

I've written a method that is going to set a bit array by passing bool parameters to be able send correct command ...
0answers
79 views

### Generating Unique Subsets using Bitmasking

Given an array arr[] of integers of size N that might contain duplicates, the task is to find all possible unique subsets. Link to the judge: LINK Note: Each subset should be sorted. Example 1: ...
1answer
38 views

### Invert n bits beginning at position p of an unsigned integer

In an attempt to create a function that returns x with the n bits that begin at position p ...
2answers
179 views

### Determine whether bitwise-OR of sub-array is odd

Problem: Given an array A of N integers, you will be asked Q queries. Each query consists of two integers L and R. For each query, find whether bitwise OR of all the array elements between indices L ...
0answers
104 views

### BitVector64 implementation

I have implemented a structure to handle BitVector64 (default System library support only 32 bits). In the implementation i have added some custom method to manipulate bits inside the vector. I would ...
1answer
83 views

### Generically convert bytes to integers

I wanted to know If there was a way to make it more versatile or shorter/simpler. Here's the code: ...
2answers
342 views

### Random alphanumeric string generator function (C, Windows, bcrypt.h)

The function uses the Windows "Cryptography API: Next Generation" (bcrypt.h)'s BCryptGenRandom function to generate ...
1answer
65 views

### Bitarr class optimization C++

I have implemented a bitarr class that does bit manipulations. I would love to know if there is any way to make the code more optimized. Any input would be much appreciated. Thank you! Note: int main()...
2answers
281 views

### Bit manipulator (reader / writer)

Please take a review of my simple bit manipulator: ...
2answers
458 views

### How to optimize bitwise get/set/clear of ranges of bits on 8-bit integers in JavaScript?

I have been working for a few days on writing get, set, and clear bitwise functions in ...
1answer
51 views

### Array-like data structure for fixed sized types with non-machine-word sizes

I am writing an array-like data structure for types other than 8 16 32 64 – the usual type sizes. Ideally, my interface is the following for addressing the array. ...
1answer
276 views

### Parsing a sequence of bits out of a bit field

For homework, I had to parse CPUID instruction output in C, which required a lot of specific bit-manipulation like: (eax & CACHE_LEVEL) >> 5 I ...
0answers
40 views

### Implementing a Hilbert-like space-filling-curve conversion in Rcpp

I have written a series of functions that are designed to create a space-filling curve (similar to a Hilbert Curve) that is intended for symmetric matrices (as opposed to a square region). I plan to ...
1answer
74 views

### Factoring the powers of 2 in Python

The powers of 2 are trivial to factor because all powers of 2 have one 1-bit and the rest 0-bits. Just iterate minus one 0-bit as follows: 10000,1000,100,10,1. And then convert the binary strings into ...
1answer
110 views

### Von Neumann random bytes debiasing

I need to create a method to debias biased bytes from the method get_raw_bytes(length) using von Neumann debiasing method. Von ...
1answer
83 views

### ROT128 byte-transformation encoding

I'd like some feedback on code I wrote to obfuscate text on-disk. The basic idea is the same as ROT13 (which is implemented in the Python standard library), except instead of rotating the English ...
1answer
293 views

### LeetCode: Sum of Two Integers C#

https://leetcode.com/problems/sum-of-two-integers/ Calculate the sum of two integers a and b, but you are not allowed to use the operator + and -. Example 1: Input: a = 1, b = 2 Output: ...
1answer
96 views

### Swapping Nibbles

I have small (<250 bytes) chunk of binary data, where I know that almost always, the first nibble is going to be zero 0. For example, in hex: ...
3answers
225 views

### Bit shift 256 bits

I have a working solution to my problem, but I'm less than satisfied with the result, both when it comes to style and performance. In short, I need to be able to shift 256 bits of data, say an array ...
2answers
154 views

### Bitmap in Bitmap (Black & white)

Below is my attempt at bitmap in bitmap searching using 1bpp bitmaps. Any suggestions on how I can reduce complexity and improve speed? Any comment is appreciated. ...
1answer
39 views

### Basic Subnet Mask Calculator + A Little Extra

For my Networking class, we learned about subnetting and subnet masks. I decided to write a little "calculator" (a generous term) that when given n-many network ...
2answers
133 views

### converting bits binary to bcd

I wrote a code that requests user input and then converts binary to bcd then back to binary using bitwise operations. While I think my code is good I want to know if there is a better way to write the ...
3answers
191 views

### Adding two n and m bit binary numbers

Recently I was studying bitwise operators and bit-manipulation algorithms and I found out an algorithm to add two binary numbers. Pseudocode is as follows: ...
1answer
149 views

### Interlock of some equipments in electrical power system using simple Arduino Uno code [closed]

I'm trying to implement some logic functions essential to control a small power system consisting of 2 Transformers labeled T1 and T2, 2 Generators (G1 and G2) and a bus tie (BT). I'm not going to ...
2answers
428 views

### Proper Case Conversion (Performance)

I wrote a simple function that converts an array of words into proper case (using bitwise operations) and returns the array. I performed a simple test using ...
3answers
558 views

### “Fast strlen” in C using scalar bithacks

I've translated an implementation of strlen in x86 assembly to C and added alignment checking: ...
1answer
841 views

### Decoding of binary data (AIS) from socket

I am currently working on a AIS message decoder written in pure Python. It's just a little project to teach me some things about binary data, decoding, etc. Because I am only programming for about a ...
2answers
189 views

### Byte extension methods for common bitwise operations

I'd like to learn how I can optimize the following byte extension methods. I'm targeting .NET Standard 2.0 but I'm curious if there are any ways to go about some of this functionality using features ...
1answer
3k views

### overload c++ enum class operators and enable check value set

I use c++ 11 enum class usually instead of the old enums because many enums can contain the same value but as known they don't have the bitwise operators out of the box so we should define them ...
1answer
57 views

### Invert bits of a number in clojurescript

Doing a challenge to print the number that you would get if you convert a given number to binary, invert its bits, then convert back to decimal. I decided to give it a run in clojurescript (which I ...
1answer
288 views

### Invert bits of binary representation of number

This is the code I came up with. I added comments to make the solution more verbose. ...
1answer
56 views

### LeetCode Count number of set bits solution

Question - Write a function that takes an unsigned integer and return the number of '1' bits it has (also known as the Hamming weight). ...
2answers
1k views

### Bouncing map back into its bounds, after user dragged it out

Users like exploring maps, seeing all that is around. However they tend to go too far. To prevent the map from getting lost to the user it bounces back into the set bounds, as defined by a rectangle. ...
2answers
84 views

### Count all X-shaped bits from 8 integers

I am given 8 positive 32-bit integer numbers. The task is to write program to count all X-bits. X-bits are groups of 9 bits (3 rows x 3 columns) forming the letter "X". task is to count all X-bits ...
1answer
76 views

### Set a specific bit to a specific value [closed]

This is the code I came up with: ...
1answer
2k views

### pythonic way to split bytes

I have incoming data from an absolute rotary encoder. It is 24 bits wide. 12 bits are the number of turns and 12 bits are the angle. I'm reading the data with an Arduino and sending it to the ...
1answer
88 views

### Binary Trie in F#

I have this little exercise writing a binary trie in F#. In C# it can be done in few lines, but here it became more complicated than I had expected (especially the ...
1answer
186 views

### Indeterminate-length big-endian to little-endian conversion in Python

I have a need to convert wire encoding (big-endian) to little-endian in Python. The conversion needs to happen as a separate function; I am not allowed to change the function that reads the byte ...
2answers
131 views

### Templated division by a power of 2

I've implemented a div_by_power_of_2() function, which lets me force the compiler to use left-shifting rather than proper division, in cases when the developer know ...
1answer
83 views

### Fun crypto problem: Exploiting a vulnerable encryption scheme with Python

I came across a question asked here and here on the Crypto Stack Exchange site, and decided to analyze it as a kind of case study. To demonstrate the concept, I wrote a short python script depicting ...
2answers
179 views

### Find out whether number is of Power of Two

The task is taken from leetcode Given an integer, write a function to determine if it is a power of two. Example 1: Input: 1 Output: true Explanation: 20 = 1 Example 2: ...
2answers
525 views

### Register “%b” conversion specifier

I'm writing a library to register the b, B conversion specifiers and make them work the closest possible to ...
1answer
85 views

### Go command-line tool to do some simple byte manipulation

I have some files containing 16-bit words in big-endian order, and a tool to process them that assumes little-endian order. I therefore need to swap the order of each pair of bytes in my files. This ...
0answers
335 views

### Java code to convert BigDecimal to/from .NET decimal

Background In many languages we have built-in data types for representing decimal floating point numbers. In .NET that's decimal, and in Java we have ...
0answers
521 views

### RGB to YCbCr conversion in Java

I found a Go language code to do RGB to YCbCr conversion from here! I ported it to Java: ...
1answer
215 views

### Division without using division, multiplication, or modulus operators

The task Implement division of two positive integers without using the division, multiplication, or modulus operators. Return the quotient as an integer, ignoring the remainder. My solution <...
1answer
2k views

### Python binary calculator

My task was to build a calculator in Python supporting binary addition etc. To begin I define a couple of custom exceptions : ...