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Is a Java hashmap search really O(1)?
I've seen some interesting claims on SO re Java hashmaps and their O(1) lookup time. Can someone explain why this is so? Unless these hashmaps are vastly different from any of the hashing algorithms I was bought up on, there must always exist a dataset that contains collisions.
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Closing multiple issues in Github with a commit message
I know you can close issues by putting closes #1 or fixes #1 in the commit message. What is the best way to close multiple issues in the same commit message?
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How do I check the difference, in seconds, between two dates?
...es, use total_seconds like this:
import datetime as dt
a = dt.datetime(2013,12,30,23,59,59)
b = dt.datetime(2013,12,31,23,59,59)
(b-a).total_seconds()
86400.0
#note that seconds doesn't give you what you want:
(b-a).seconds
0
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Iterating over each line of ls -l output
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Set IFS to newline, like this:
IFS='
'
for x in `ls -l $1`; do echo $x; done
Put a sub-shell around it if you don't want to set IFS permanently:
(IFS='
'
for x in `ls -l $1`; do echo $x; done)
Or use while | read instead:
ls -l $1 | while read x; do echo $x; done
One more ...
JavaScript % (modulo) gives a negative result for negative numbers
According to Google Calculator (-13) % 64 is 51 .
11 Answers
11
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HEAD and ORIG_HEAD in Git
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331
HEAD is (direct or indirect, i.e. symbolic) reference to the current commit. It is a commit that...
Numpy first occurrence of value greater than existing value
I have a 1D array in numpy and I want to find the position of the index where a value exceeds the value in numpy array.
7 A...
Detect iPad users using jQuery?
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317
iPad Detection
You should be able to detect an iPad user by taking a look at the userAgent pro...