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Why is std::map implemented as a red-black tree?
...1) or O(log n) because the main operation is already O(log n). even after all the slightly extra work that AVL trees do results in a more tightly balanced tree which leads to slightly faster lookups. so it is a perfectly valid tradeoff and does not make AVL trees inferior to red-black trees.
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How to use Session attributes in Spring-mvc
...ntage:
@session may use more memory in cloud systems it copies session to all nodes, and direct method (1 and 5) has messy approach, it is not good to unit test.
To access session jsp
<%=session.getAttribute("ShoppingCart.prop")%>
in Jstl :
<c:out value="${sessionScope.ShoppingCart.p...
Is there an eval() function in Java? [duplicate]
...to do some math seems like a huge waste. But you're right, it works, especially if efficiency isn't a priority.
– Sasha Chedygov
Apr 9 '10 at 4:21
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In Javascript, how to conditionally add a member to an object?
I would like to create an object with a member added conditionally.
The simple approach is:
22 Answers
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How to round up the result of integer division?
...ause it only uses it once, you don't need to store the recordsPerPage specially if it comes from an expensive function to fetch the value from a config file or something.
I.e. this might be inefficient, if config.fetch_value used a database lookup or something:
int pageCount = (records + config.f...
Iterating over every two elements in a list
... y in pairwise(l):
print "%d + %d = %d" % (x, y, x + y)
Or, more generally:
from itertools import izip
def grouped(iterable, n):
"s -> (s0,s1,s2,...sn-1), (sn,sn+1,sn+2,...s2n-1), (s2n,s2n+1,s2n+2,...s3n-1), ..."
return izip(*[iter(iterable)]*n)
for x, y in grouped(l, 2):
print...
When is it practical to use Depth-First Search (DFS) vs Breadth-First Search (BFS)? [closed]
...st rules of thumb; you'll probably need to experiment.
Another issue is parallelism: if you want to parallelize BFS you would need a shared datastructure between threads, which is a bad thing. DFS might be easier to distribute even between connected machines if you don't insist on the exact order of...
How can I add the sqlite3 module to Python?
Can someone tell me how to install the sqlite3 module alongside the most recent version of Python?
I am using a Macbook, and on the command line, I tried:
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Rails Migration: Remove constraint
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ndnenkov
32.3k99 gold badges6060 silver badges9090 bronze badges
answered Jan 31 '14 at 6:49
deepakdeepak
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Collisions when generating UUIDs in JavaScript?
...rom Math.random(). For some browsers the entropy is as low as just 41 bits all together. Calling Math.random() multiple times won't raise the entropy. If you really want unique v4 UUIDs you need to use a cryptographically strong RNG that produces at least 122bit entropy per UUID generated.
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