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.
306
questions
8
votes
2answers
87 views
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 ...
2
votes
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.) ...
2
votes
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 ...
2
votes
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
...
1
vote
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:
...
3
votes
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 ...
1
vote
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 ...
3
votes
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 ...
4
votes
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:
...
3
votes
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 ...
5
votes
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()...
3
votes
2answers
281 views
5
votes
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 ...
3
votes
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.
...
7
votes
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 ...
3
votes
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 ...
0
votes
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 ...
3
votes
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 ...
5
votes
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 ...
1
vote
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: ...
3
votes
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:
...
7
votes
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 ...
2
votes
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.
...
3
votes
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 ...
4
votes
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 ...
2
votes
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:
...
-1
votes
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 ...
9
votes
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 ...
8
votes
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:
...
4
votes
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 ...
3
votes
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 ...
3
votes
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 ...
2
votes
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 ...
4
votes
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.
...
1
vote
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).
...
10
votes
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.
...
6
votes
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 ...
3
votes
1answer
76 views
5
votes
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 ...
4
votes
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 ...
2
votes
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 ...
5
votes
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 ...
9
votes
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 ...
4
votes
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:
...
7
votes
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 ...
1
vote
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 ...
3
votes
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 ...
4
votes
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:
...
3
votes
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
<...
4
votes
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 :
...
