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Why `null >= 0 && null
I had to write a routine that increments the value of a variable by 1 if its type is number and assigns 0 to the variable if not, where the variable is initially null or undefined .
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How to round a number to significant figures in Python
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146
You can use negative numbers to round integers:
>>> round(1234, -3)
1000.0
Thus if...
Memcached下一站：HandlerSocket！ - 更多技术 - 清泛网 - 专注C/C++及内核技术
...相应的安装过程再写一遍。
首先要确保已经安装了MySQL5.1以上的版本，我用的是Ubuntu操作系统，事先已经用apt安装了MySQL5.1.37，同时还需要相应的mysql_config，如果是Ubuntu的话，可以：
shell> aptitude install libmysqld-dev
注：如果你...
Is this a “good enough” random algorithm; why isn't it used if it's faster?
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14 Answers
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Small Haskell program compiled with GHC into huge binary
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215
Let's see what's going on, try
$ du -hs A
13M A
$ file A
A: ELF 64-bit LSB executa...
Fastest way to convert string to integer in PHP
Using PHP, what's the fastest way to convert a string like this: "123" to an integer?
8 Answers
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Formula to determine brightness of RGB color
...ightness? Luminance?
Luminance (standard for certain colour spaces): (0.2126*R + 0.7152*G + 0.0722*B) [1]
Luminance (perceived option 1): (0.299*R + 0.587*G + 0.114*B) [2]
Luminance (perceived option 2, slower to calculate): sqrt( 0.241*R^2 + 0.691*G^2 + 0.068*B^2 ) → sqrt( 0.299*R^2 + 0.587*G^...
Peak signal detection in realtime timeseries data
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What is a good regular expression to match a URL? [duplicate]
...ure URL starts with HTTP/HTTPS:
https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_\+.~#?&//=]*)
If you do not require HTTP protocol:
[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_\+.~#?&//=]*)
To try this out see http://regex...
What is the fastest integer division supporting division by zero no matter what the result is?
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Inspired by some of the comments I got rid of the branch on my Pentium and gcc compiler using
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