# Questions tagged [bitwise]

For challenges involving bitwise commands or manipulation of numbers at the bit level

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### Double bit rotation to the right [closed]

Given a positive integer as input, output that integer, but with its bits rotated two times to the right. Also, think of the number as a donut of bits, eg. ...
109 views

### Calculate the truncated log2 of some unsigned integer [duplicate]

Definition Given some number, x calculate the smallest number i such that 2i≥x. This is not a duplicate of this question. It is slightly different in that an input of 16 should yield an output of 4 ...
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Introduction Dr. Leslie Lamport, of the eponymous Lamport one-time signature scheme, is getting rather old. But he can't die until his most famous algorithm gets all the kinks ironed out! In ...
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### Golf this Thumb-2 Constant!

One thing that is constantly frustrating when golfing ARM Thumb-2 code is generating constants. Since Thumb only has 16-bit and 32-bit instructions, it is impossible to encode every immediate 32-bit ...
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### Find the "Bittiest" Number [closed]

The Challenge Given a list of integers, the "bittiest" number among them is the one with the most bits on - that is, the largest amount of bits set to 1. Write a function (or a program) that ...
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### "Bit-borrow" two numbers

Did you know that a small number can borrow bits from a larger number? Here's an example. Let's say our two numbers 5 and 14. First, write them out in binary: ...
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### Mean bits: an average challenge

Given an integer N >= 1, output the mean number of bits in an integer from 0 to N - 1 Specification The output can be calculated as the sum of the number of bits in the binary representation of each ...
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### Compute CRC32 Hash

Credits This challenge originated from @miles. Create a function that computes the CRC32 hash of an input string. The input will be an ASCII string of any length. The output will be the CRC32 hash of ...
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### Generate a parity bit

A parity bit, is one of the simplest forms of a checksum. First, you have to pick the parity, even or odd. Let's say we pick even. Now, we need a message to transmit. Let's say our message is "...
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### Split a byte array into a bit array

Write a function that when given a buffer b (1 - 104857600 bytes long) and a number of bits n (1 <= n <= 64), splits the ...
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### The XOROR sequence

Cellular Automata are truly fascinating. The ones that are usually talked about are the binary ones, i.e., the ones representable by a number. However, those, in my opinion, have been done to death. ...
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Introduction There are often times that we have challenges which require communication of some sort (such as in team KOTH), where density of information may be more important than density of code. ...
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### Bijective mapping from integers to a variable number of bits

A variable number of bits is an array of 0 or more bits. So [0, 1] is a variable number of bits, but so is []. Write a function ...
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### Cheating a multiple choice test

Introduction While studying, I tried to come up with several ways to cheat a multiple choice test. It basically is a compressed version of the multiple choice answers. The method goes as following: ...
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### Xorting an array

Conceptually, this challenge is really simple. You're given a list of non-negative integers ai. If possible, find a non-negative integer ...