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Converting timestamp to time ago in PHP e.g 1 day ago, 2 days ago…
I am trying to convert a timestamp of the format 2009-09-12 20:57:19 and turn it into something like 3 minutes ago with PHP.
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How is a CRC32 checksum calculated?
... + x8 + x7 + x5 + x4 + x2 + x + 1
Wikipedia
CRC calculation
Or in hex and binary:
0x 01 04 C1 1D B7
1 0000 0100 1100 0001 0001 1101 1011 0111
The highest term (x32) is usually not explicitly written, so it can instead be represented in hex just as
0x 04 C1 1D B7
Feel free to count...
Explain the use of a bit vector for determining if all characters are unique
...ay be a little bit faster, because operations with bits are very low level and can be executed as-is by CPU. BitVector allows writing a little bit less cryptic code instead plus it can store more flags.
For future reference: bit vector is also known as bitSet or bitArray. Here are some links to thi...
Get a specific bit from byte
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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 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
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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:
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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...
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:
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Difference between float and decimal data type
What difference does it make when I use float and decimal data types in MySQL?.
12 Answers
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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.
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