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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3
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1answer
50 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: ...
4
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2answers
97 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
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2answers
99 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
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1answer
28 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
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2answers
59 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
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3answers
164 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: ...
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1answer
65 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
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2answers
410 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
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3answers
202 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
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1answer
181 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
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2answers
97 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
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1answer
299 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
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1answer
30 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
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1answer
75 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. ...
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1answer
41 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). ...
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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
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2answers
82 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 ...
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1answer
69 views

Set a specific bit to a specific value [closed]

This is the code I came up with: ...
5
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1answer
156 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
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1answer
78 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 ...
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1answer
47 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
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2answers
124 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 ...
8
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0answers
58 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 ...
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3answers
145 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: ...
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2answers
210 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 ...
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1answer
77 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 ...
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0answers
119 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 ...
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0answers
226 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
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1answer
115 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 <...
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1answer
419 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 : ...
3
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1answer
3k views

Hamming Distance in Python

I was solving this Leetcode challenge about Hamming Distance. Would love feedback on my syntax and code style. Here's the challenge description: The Hamming distance between two integers is the ...
6
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3answers
258 views

Encoding 0/1 bits to 0/255 bytes in C++

I need to map a sequence of bits that represents a float into a sequence of bytes by this rule: the value 1 maps to the value 255 and the value 0 maps to the value 0. This is the code I have now: <...
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5answers
1k views

Largest binary gap

I took a task from Codility to find longest sequence of zeros in binary representation of an integer. For example, number 9 has binary representation 1001 and contains a binary gap of length 2. ...
3
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2answers
461 views

Change Arithmetic Right Shift to Logical Right Shift

The following code is a solution to a textbook (Bryant&O'Hallaron: Computer Systems A programmer's Perspective 2nd Ed) problem in bit-level data manipulation (attempted for the challenge, not a ...
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1answer
43 views

Implementing carryless multiplication using normal multiplication

In carryless multiplication the partial products are XORed (ie addition without carry) together rather than added normally. The partial products themselves are still the product of a power of two (...
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2answers
67 views

Given an integer number, invert its bits. You cannot use the ~ operator

Here is my code: ...
0
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1answer
28 views

Given an integer, return its binary representation. You cannot use any Integer.toXXXString methods

Here is my code: ...
4
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2answers
163 views

C bit mask calculator written using GTK+ 3

I've been studying C on my own using K&R 2nd Edition, and started exploring GTK+ to practice some of the concepts I've learned by making GUI applications. This is the first GUI application I've ...
6
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4answers
220 views

Efficiently swapping the first and last five bits in an unsigned 16-bit integer in C

I'm programming on an 8-bit Z80 embedded system, and encountered a problem. The program needs to render some pixels to the screen. The color is stored as RGB565 format as a 16-bit unsigned integer, ...
2
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1answer
99 views

C++ class for a flag register in a Chip8 emulator

In order to learn C++ I decided to code a Chip8 emulator following a tutorial. When I came across the idea of a flag register and decided it would be fun to implement in order to get familiar with ...
1
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1answer
65 views

Maximise XOR of two elements

I have a number x and I need to choose another number y from the given range [l, r] such ...
0
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1answer
56 views

Kademlia bucketing

Kademlia is a DHT (distributed hash table) which uses a specific type of routing table, dependent on the Hamming distance between the "addresses" of two peers on the network. I'm attempting to ...
5
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2answers
171 views

Circular-shift with variable bitlength

For some memory masking operations I need a bitwise-rotation functionality for unsigned integral types. I came across solutions based on the wiki article, but have not found a variation for a function ...
3
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1answer
109 views

K&R Exercise 2-6 : Inserting part of a bitset into another

"Inserting" part of a bitset into another This is Exercise 2-6 on the K&R book, 2nd edition. The reader is asked to: Write a function setbits(x,p,n,y) that returns x with the n bits that begin ...
1
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1answer
215 views

Adder method of a binary calculator

This is the adder method of my binary calculator. I did not cover for the case that someone passes a non binary number into the calculator yet. I am pretty sure I have covered every other edge case ...
5
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3answers
202 views

Basic binary number container

Summary: a templated class, whose main purpose is to store a binary representation of a decimal number. I choose array of booleans as a storage, since bitset was forbidden. One of the requirements was ...
3
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4answers
175 views

Find the longest length of sequence of 1-bits achievable by flipping a single bit from 0 to 1 in a number

Problem Statement The problem is defined in the book as following: 5.3 You have an integer and you can flip exactly one bit from 0 to ...
4
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2answers
115 views

Checking if a number is a power of 2 without loops

I made a short program which checks if a number is a power of 2 without using any loops. The idea: A number which is a power of 2 must have only one bit "1" ( ex: 8= 1000, 4=100 and so on). Suppose ...
2
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0answers
81 views

Kaitai Struct: shift rotate >1 byte groups

This is an implementation of rotation (cyclic shift) of many-byte groups to the left. Rotate right is supported as negative amount. I would like to request, if someone would be willing, to review this ...
4
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1answer
73 views

Check digital input signals that is sent as an integer using bitwise checking

I have a program that works with a hardware via an ActiveX API. The API have events that is triggered by the hardware. In the hardware there is an IO card. There is 16 in and 16 out. Changes in input ...

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