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Why is the time complexity of both DFS and BFS O( V + E )
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But every vertex must be extracted from queue, and this is log(|Q|) What about this part?
– Yola
Jan 24 '16 at 10:56
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How to get duplicate items from a list using LINQ? [duplicate]
...duplicated in the source list, you could apply Distinct to the resulting sequence or use the solution given by Mark Byers.
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The identity used to sign the executable is no longer valid
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It works for me as well. command + Q to exit XCode and restart. Cheers!
– Joey
Aug 30 '13 at 4:38
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Run a single migration file
...just run the code directly out of the ruby file:
rails console
>> require "db/migrate/20090408054532_add_foos.rb"
>> AddFoos.up
Note: newer versions of rails may require AddFoos.new.up rather than AddFoos.up.
An alternative way (without IRB) which relies on the fact that require retu...
MySQL check if a table exists without throwing an exception
What is the best way to check if a table exists in MySQL (preferably via PDO in PHP) without throwing an exception. I do not feel like parsing the results of "SHOW TABLES LIKE" et cetera. There must be some sort of boolean query?
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How to convert a Django QuerySet to a list
...tools
ids = set(existing_answer.answer.id for existing_answer in existing_question_answers)
answers = itertools.ifilter(lambda x: x.id not in ids, answers)
Read when QuerySets are evaluated and note that it is not good to load the whole result into memory (e.g. via list()).
Reference: itertools....
Generating a PNG with matplotlib when DISPLAY is undefined
...config/matplotlib'/matplotlibrc (as an example, seehttp://matplotlib.org/faq/troubleshooting_faq.html#locating-matplotlib-config-dir). See also matplotlib.org/users/customizing.html, which has an example config file at the bottom of the page. Find "agg" on that page and you'll see the config option ...
git reset --hard HEAD leaves untracked files behind
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My common command is git clean -qfdx here. Remove everything and do it silently.
– aragaer
May 25 '13 at 17:51
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How do I 'svn add' all unversioned files to SVN?
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svn add --force * --auto-props --parents --depth infinity -q
Great tip! One remark: my Eclipse adds new files to the ignore list automatically. It may be a matter of configuration, but anyhow: there is the --no-ignore option that helps.
After this, you can commit:
svn commit -m 'A...
How do I create a unique ID in Java? [duplicate]
I'm looking for the best way to create a unique ID as a String in Java.
11 Answers
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