# Tagged Questions

Questions related with (base 2) representation of numbers and their unique properties arising out of number representation.

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### How to find Bitwise AND of all numbers for a given range?

How can I find Bitwise AND of all numbers for a given range say from A to B, including both? I found a beautiful answer for finding XOR for such range. http://stackoverflow.com/a/10670524/2046703How ...
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### Classification of numbers on the base of binary representation

The problem is the following. I would like to find a simple algorithm or principle of classification of numbers regarding their presentation in binary form. Let's consider an example. The numbers by ...
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### Is Cantor's diagonal argument dependent on the base used?

Applying Cantor's diagonal argument to irrational numbers represented in binary, one and only one irrational number can be generated that is not on the list. Wikipedia image: But if you change ...
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### Unfair coin probability (P) that results in 0.5% chance of getting x tails out of y tosses?

For an unfair coin toss that produces heads with probability P, what is the value of P that will result in 0.5% (i.e. 0.005) chance of getting exactly x tails out of y tosses? i.e. is there a general ...
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### An algorithm to binary division

there is some algorithms for binary division in computer architecture. first: resorting which is described in Computer Architecture of D. Patterson second: non-resorting which is described in Computer ...
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### distribution probability question involving binary functions for certain n<2^10

For any positive integer n, let G(n) be the number of pairs of adjacent bits in the binary representation of n which are different. For example, G(10)=3 because the bits of $1010_2$ change at all ...
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### Probability of getting a Column full rank binary matrix

Suppose I have a $m \times n$ ($m>>n$) zero matrix (all of the elements are $0$). I want to flip $k$ ($k \ge n$ and can be controlled by the user) elements of the matrix randomly. After this ...
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### How to prove that all powers of two minus one have only 1's when in binary representation?

It just came to my mind that all powers of two, when represented in binary format, are composed of only 1's, not 0's. I can see some logic behind it, however I can't seem to come up with an actual ...
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### XOR function over binary vectors

I didn't really know how to name this question, it has been bothering me for some time: You are given n binary vectors of dimension $d: x_1,\cdots,x_n$; $x_i = x_{i_1},\cdots,x_{i_d}$. You are also ...
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### how binary quantile regression divides the dependent variable into quantiles

I am not very clear with binary quantile regression. As if it was ordinary quantile regression, it would divide the dependent variable's value by its ascending value into quantiles. But I cannot ...
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### 4-bit number to decimal number

Juts like the title says: a code to convert a 4-bit number into a decimal equivalent number without using any fucntion from octave's library. Not a clue! We consider the input a binary number ...
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### Finding the binary representation of the $n$th Fibonacci term

Objective: To find the binary representation ( or no. of 1's in binary representation) of nth term in Fibonacci sequence where n is of the order 10^6. My current approach: Find nth term (in decimal) ...
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### What is 6.5 in binary? [duplicate]

I just stumbled across a problem I never actually thought about before: decimals in binary. Can someone explain how to do it? Thanks! Note: If possible, I'd like the answer in decimals not fractions, ...
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### Convert the following hexadecimal representation of 2’s complement binary numbers to decimal numbers.

I need to convert the following hexadecimal representation of 2’s complement binary numbers to decimal numbers I am unsure if I am doing it correctly or am I missing a step? a. xF0 b. x7FF c. ...
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### Give the idempotent generators of the four binary QR codes C1 , C2 , C3 , C4 , of length 7.

I'm having trouble on some homework. This is the last problem and I can't figure it out. Can anyone help or point me in the right direction? Thanks! For each code Ci , 1 ≤ i ≤ 4, from part (a), give ...
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### Proving properties of binary relations

Attempting to find answers to solve these questions. I've been looking all over the web for references since my textbooks aren't being helpful. Now, I'm still at the starting point. ...
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### how to find the binary expansion of any number in the unit interval [0,1]

For each integer $n\geq 1$ and $x\in [0,1]$, define $f_n(x)=x_n$ where $x_n$ is the $n$th binary digit of x. If x is a number with two binary expansions, use the expansion that ends with infinitely ...
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### Counting binary strings that have atmost k consecutive 0's

I know how to count how many binary strings with length n and having exactly k 0's are there but i am not able to find a way to count the number of binary strings that have exactly x 0's and y 1's and ...
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### binary representation of a fraction in two's complement

Could any one please explain what is a 16-bit two's-complement representation of -0.375 and the steps to calculate it? Also, what happens if I convert it back to decimal? Thanks
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### Arithmetic Overflow and Underflowing

I am a bit unclear about underflowing in terms of binary representation. Let's say that an unsigned 8-bit variable gets overflown from the addition of $150+150$. A signed 8-bit variable gets ...
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### How is OEIS sequence A120933 'maximal leading nondecreasing subword ' to be understood?

For n=2 we only have these four binary words: 00 01 10 11 What is the procedure for calculating by hand T(2,1) and T(2,2)? I'm trying to understand the reasoning behind this sequence as I can't see ...
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### Number of ways to express a binary number in a certain way

So I'm working on a problem where I get to a point where I have to count the number of solutions to an equation or at least find a decent upper bound to be used in an estimate I need later. The ...
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### Given two dot products with the same vector in a prime finite field of 2 (Galois Field), how can one figure out future dot products?

I've stumbled upon an interesting "rule" derivation for the value of a dot product in $\mathbb{R}^{n}$ like this: Given an arbitrary vector $\vec a \in \mathbb{R}^{n}$ and the values of two dot ...
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### Quick logarithm calculation

In coming up with an algorithm for finding log (10) base 2, these are my thoughts. I wanted to know if this makes sense and how could I truly make it more efficient. The requirements are strictly not ...
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### Find the solution of binary xor operator equation

I am working in binary xor operator $\mathbb Z_2$. I have to resolve my problem such as $$\begin {cases} x_1+x_2+x_3=1\\ x_1+x_2=0\\ x_1+x_3=1\\ \end {cases}$$ Could you suggest to me any method to ...
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### Mathematical Terms for Binary Operations

I'm trying to represent binary operations on numbers in mathematically correct terminology. For example given two binary numbers: 42 : 101010 13 : 001101 I want ...
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### Will the Russian Peasant work with anything other than base 2?

The Russian peasant method involves doubling and halving by 2. Therefore you will get exact remainders of either 1 or 0, which perfectly represents one of the multiplicands in binary form. I just ...
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### Explanation of division/reduction in a binary Galois Field using bit-shifts

I've seen a lot of algorithms reducing the result of a multiplication in a Binary Field by using only bit-shifts and XOR. The number of positions to shift seems to be derived from the polynomial, but ...
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### How many binary sequences of length n are there that contain exactly m occurrences of the pattern 01?

I thought there were n-1 places between the first and last digit. In these places I hypothesized there are switches that change (from 0->1 or 1->0) For ...
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### Polynomial Arithmetic Modulo 2 (CRC Error Correcting Codes)

I'm trying to understand how to calculate CRC (Cyclic Redundancy Codes) of a message using polynomial division modulo 2. The textbook Computer Networks: A Systems Approach gives the following rules ...
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### Binary overflow

Which of the following hexadecimal numbers, representing signed 16-bit binary numbers, results in overflow when multiplied by 4? Here, a negative number is represented in 2's complement. ...
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### Determine whether or not a binary number is divisible by $3$

Let $K$ be a natural number with $n$ binary digits. Is there an $O(n)$ method for deciding whether or not $K$ is divisible by $3$? $3|K \iff d_1-d_2+d_3-d_4\dots\pm d_n=0$ works correctly up to ...
I am solving the following exercise: for $n \in \mathbb{N}$ and $a_1,a_2, \ldots ,a_n \in \{0,1\}$ we define:  I(a_n, \ldots , a_n) := \left \lbrack \sum_{i=1}^n \frac{a_i}{2^i}, ...