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Initializing a list to a known number of elements in Python [duplicate]
...x in xrange(N)]
10 loops, best of 3: 109 ms per loop
>>> def fill_list1():
"""Not too bad, but complicated code"""
a = [None] * N
for x in xrange(N):
a[x] = x**2
>>> %timeit fill_list1()
10 loops, best of 3: 126 ms per loop
>>> def fill_list2():
"...
Default template arguments for function templates
...
typename Comp = std::less<
typename std::iterator_traits<Iterator>::value_type> >
void sort(Iterator beg, Iterator end, Comp c = Comp()) {
...
}
C++0x introduces them to C++. See this defect report by Bjarne Stroustrup: Default Template Arguments for Functio...
Why aren't Java Collections remove methods generic?
... and HashSet are checking for the hash code, and TreeSet/Map are using the ordering of the elements. Still, they fully implement Collection.remove, without breaking its contract (if the ordering is consistent to equals). And a varied ArrayList (or AbstractCollection, I think) with the equals call tu...
How does virtual inheritance solve the “diamond” (multiple inheritance) ambiguity?
...he grandfather!
BUT you still need to specify the methods to be virtual in order to get the methods correctly overrided...
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Reshape three column data frame to matrix (“long” to “wide” format) [duplicate]
...ical: should the row names be in ascending (FALSE) or in descending (TRUE) order?
#' @param coldecreasing logical: should the col names be in ascending (FALSE) or in descending (TRUE) order?
#' @param default_value numeric: default value of matrix entries if no value exists in data.frame for the ent...
How can I count the occurrences of a list item?
...by a constant factor of approximately 2.
Here is the script I used:
from __future__ import print_function
import timeit
t1=timeit.Timer('Counter(l)', \
'import random;import string;from collections import Counter;n=1000;l=[random.choice(string.ascii_letters) for x in range(n)]'
...
JPA EntityManager: Why use persist() over merge()?
...
Thus there is no possibility to change operation order for orphanremoval=true?
– gstackoverflow
Sep 14 '17 at 16:09
...
Random float number generation
...ften done like this:
srand (static_cast <unsigned> (time(0)));
In order to call rand or srand you must #include <cstdlib>.
In order to call time, you must #include <ctime>.
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How to create NS_OPTIONS-style bitmask enumerations in Swift?
...le's documentation about interacting with C APIs, they describe the way NS_ENUM -marked C-style enumerations are imported as Swift enumerations. This makes sense, and since enumerations in Swift are readily provided as the enum value type it's easy to see how to create our own.
...
Can jQuery provide the tag name?
...
$(this).attr("id", "rnd" + $(this).attr("tag") + "_" + i.toString());
should be
$(this).attr("id", "rnd" + this.nodeName.toLowerCase() + "_" + i.toString());
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