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What is tail recursion?
...cursion, the typical model is that you perform your recursive calls first, and then you take the return value of the recursive call and calculate the result. In this manner, you don't get the result of your calculation until you have returned from every recursive call.
In tail recursion, you perfor...
Format output string, right alignment
...ew = '{:>12} {:>12} {:>12}'.format(word[0], word[1], word[2])
And here's how to do it using the old % syntax (useful for older versions of Python that don't support str.format):
line_new = '%12s %12s %12s' % (word[0], word[1], word[2])
...
Boolean Field in Oracle
...
flags that Oracle's data dictionary views use, selecting 'Y' for true
and 'N' for false. However, to interact correctly with host
environments, such as JDBC, OCCI, and other programming environments,
it's better to select 0 for false and 1 for true so it can work
correctly with the getBoo...
Why does C++ rand() seem to generate only numbers of the same order of magnitude?
In a small application written in C/C++, I am facing a problem with the rand function and maybe the seed :
9 Answers
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Static methods in Python?
...should only be used if you have to support ancient versions of Python (2.2 and 2.3)
class MyClass(object):
def the_static_method(x):
print(x)
the_static_method = staticmethod(the_static_method)
MyClass.the_static_method(2) # outputs 2
This is entirely identical to the first exampl...
Sending HTTP POST Request In Java
...ost = new HttpPost("http://www.a-domain.com/foo/");
// Request parameters and other properties.
List<NameValuePair> params = new ArrayList<NameValuePair>(2);
params.add(new BasicNameValuePair("param-1", "12345"));
params.add(new BasicNameValuePair("param-2", "Hello!"));
httppost.setEnti...
Functional programming - is immutability expensive? [closed]
...arify some points.
The “in-place” quicksort isn’t really in-place (and quicksort is not by definition in-place). It requires additional storage in the form of stack space for the recursive step, which is in the order of O(log n) in the best case, but O(n) in the worst case.
Implementing a fu...
How to replace a character by a newline in Vim
..., you’d still use \n, however. This asymmetry is due to the fact that \n and \r do slightly different things:
\n matches an end of line (newline), whereas \r matches a carriage return. On the other hand, in substitutions \n inserts a null character whereas \r inserts a newline (more precisely, it...
Debugging in Clojure? [closed]
...
There's also dotrace, which allows you to look at the inputs and outputs of selected functions.
(use 'clojure.contrib.trace)
(defn fib[n] (if (< n 2) n (+ (fib (- n 1)) (fib (- n 2)))))
(dotrace [fib] (fib 3))
produces the output:
TRACE t4425: (fib 3)
TRACE t4426: | (fib 2)
T...
Test if lists share any items in python
... generally the fastest.
There are four common ways to test if two lists a and b share any items. The first option is to convert both to sets and check their intersection, as such:
bool(set(a) & set(b))
Because sets are stored using a hash table in Python, searching them is O(1) (see here for...