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Computational complexity of Fibonacci Sequence
...es? Try an (a > 1):
an == a(n-1) + a(n-2)
Divide through by a(n-2):
a2 == a + 1
Solve for a and you get (1+sqrt(5))/2 = 1.6180339887, otherwise known as the golden ratio.
So it takes exponential time.
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Javascript event handler with parameters
...have. So, you could do this:
elem.addEventListener('click', function(a1, a2, e) {
// inside the event handler, you have access to both your arguments
// and the event object that the event handler passes
}.bind(elem, arg1, arg2));
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What is the difference between sites-enabled and sites-available directory?
...orrespondent symlink in sites-enabled. In Ubuntu you can do it like this:
a2ensite mysite (with sudo, if necessary; and without the final .conf)
And then you must reload Apache:
sudo service apache2 reload
Later, if you want to modify the configuration, you only touch the mysite.conf in sites_a...
What is a None value?
...ist.append(val)
return list
list1 = extendList(10)
list2 = extendList(123,[])
list3 = extendList('a')
print "list1 = %s" % list1
print "list2 = %s" % list2
print "list3 = %s" % list3
Now try to guess output of above list. Well, the answer is surprisingly as below:
list1 = [10, 'a']
list2 = ...
Check if a string contains a string in C++
...
123
You can try using the find function:
string str ("There are two needles in this haystack.");
...
Nested fragments disappear during transition animation
... which in turn uses getChildFragmentManager() to add fragments A1 and A2 in its onCreate like so:
16 Answers
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Decorators with parameters?
...gt; print(foo)
<function _pseudo_decor.<locals>.ret_fun at 0x10666a2f0>
functools.wraps gives us a convenient method to "lift" the docstring and name to the returned function.
from functools import partial, wraps
def _pseudo_decor(fun, argument):
# magic sauce to lift the name an...
Regex to remove all (non numeric OR period)
...ern understood as:
[\d,\.]+
Enter string to check if matches pattern
> a2.3 fjdfadfj34 34j3424 2,300 adsfa
Group 0 match: "2.3"
Group 0 match: "34"
Group 0 match: "34"
Group 0 match: "3424"
Group 0 match: "2,300"
Then for each match, remove all commas and send that to the parser. To hand...
What does [object Object] mean?
...answered Aug 21 '14 at 6:25
user123444555621user123444555621
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Regex Email validation
...ht, fail to catch at least two invalid formats: "Abc.@example.com" , "Abc..123@example.com"
– sean717
Aug 22 '12 at 5:22
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