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How to find gaps in sequential numbering in mysql?
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11 Answers
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Compare two data.frames to find the rows in data.frame 1 that are not present in data.frame 2
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Convert columns to string in Pandas
...will convert keys to valid json (and therefore your keys to strings):
In [11]: df = pd.DataFrame([['A', 2], ['A', 4], ['B', 6]])
In [12]: df.to_json()
Out[12]: '{"0":{"0":"A","1":"A","2":"B"},"1":{"0":2,"1":4,"2":6}}'
In [13]: df[0].to_json()
Out[13]: '{"0":"A","1":"A","2":"B"}'
Note: you can p...
Why is January month 0 in Java Calendar?
In java.util.Calendar , January is defined as month 0, not month 1. Is there any specific reason to that ?
16 Answers
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Code Golf: Lasers
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Perl, 166 160 characters
Perl, 251 248 246 222 214 208 203 201 193 190 180 176 173 170 166 --> 160 chars.
Solution had 166 strokes when this contest ended, but A. Rex has found a couple ways to shave off 6 more characters:
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Sorting list based on values from another list?
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15 Answers
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append to url and refresh page
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166
this should work (not tested!)
var url = window.location.href;
if (url.indexOf('?') > ...
Is log(n!) = Θ(n·log(n))?
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Remember that
log(n!) = log(1) + log(2) + ... + log(n-1) + log(n)
You can get the upper bound by
log(1) + log(2) + ... + log(n) <= log(n) + log(n) + ... + log(n)
= n*log(n)
And you can get the lower bound by doin...
Java SE 6 vs. JRE 1.6 vs. JDK 1.6 - What do these mean?
... see many different Java terms floating around. I need to install the JDK 1.6. It was my understanding that Java 6 == Java 1.6. However, when I install Java SE 6, I get a JVM that reports as version 11.0! Who can solve the madness?
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