大约有 48,000 项符合查询结果（耗时：0.0339秒） [XML]
Get a specific bit from byte
...
Easy. Use a bitwise AND to compare your number with the value 2^bitNumber, which can be cheaply calculated by bit-shifting.
//your black magic
var bit = (b & (1 << bitNumber-1)) != 0;
EDIT: To add a little more detail because there ...
How do I achieve the theoretical maximum of 4 FLOPs per cycle?
...one this exact task before. But it was mainly to measure power consumption and CPU temperatures. The following code (which is fairly long) achieves close to optimal on my Core i7 2600K.
The key thing to note here is the massive amount of manual loop-unrolling as well as interleaving of multiplies a...
How can I multiply and divide using only bit shifting and adding?
How can I multiply and divide using only bit shifting and adding?
14 Answers
14
...
Why does this Java program terminate despite that apparently it shouldn't (and didn't)?
...etely wrong. An actuator on an electron microscope went over its boundary, and after a chain of events I lost $12 million of equipment. I've narrowed down over 40K lines in the faulty module to this:
...
Why does Lua have no “continue” statement?
I have been dealing a lot with Lua in the past few months, and I really like most of the features but I'm still missing something among those:
...
Difference between float and decimal data type
What difference does it make when I use float and decimal data types in MySQL?.
12 Answers
...
Regular expression for floating point numbers
...
TL;DR
Use [.] instead of \. and [0-9] instead of \d to avoid escaping issues in some languages (like Java).
Thanks to the nameless one for originally recognizing this.
One relatively simple pattern for matching a floating point number is
[+-]?([0-9]...
How to randomize (or permute) a dataframe rowwise and columnwise?
...,]
> df2
a b c
3 0 1 0
4 0 0 0
2 1 0 0
1 1 1 0
By default sample() randomly reorders the elements passed as the first argument. This means that the default size is the size of the passed array. Passing parameter replace=FALSE (the default) to sample(...) ensures that sampling is done withou...
Equation (expression) parser with precedence?
...'ve developed an equation parser using a simple stack algorithm that will handle binary (+, -, |, &, *, /, etc) operators, unary (!) operators, and parenthesis.
...
What exactly is a C pointer if not a memory address?
...
The C standard does not define what a pointer is internally and how it works internally. This is intentional so as not to limit the number of platforms, where C can be implemented as a compiled or interpreted language.
A pointer val...