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C++ sorting and keeping track of indexes
... supply your original index vector, sort function, comparator, or automatically reorder v in the sort_indexes function using an extra vector.
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What happens if you don't commit a transaction to a database (say, SQL Server)?
...ou don't COMMIT or ROLLBACK a transaction, it's still "running" and potentially holding locks.
If your client (application or user) closes the connection to the database before committing, any still running transactions will be rolled back and terminated.
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In pure functional languages, is there an algorithm to get the inverse function?
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In some cases, yes! There's a beautiful paper called Bidirectionalization for Free! which discusses a few cases -- when your function is sufficiently polymorphic -- where it is possible, completely automatically to derive an inverse function. (It also discusses what makes...
Python argparse: Make at least one argument required
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args = vars(parser.parse_args())
if not any(args.values()):
parser.error('No arguments provided.')
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Explicitly select items from a list or tuple
... myBigList[i] for i in [87, 342, 217, 998, 500] ]
20.6 usec: map(myBigList.__getitem__, (87, 342, 217, 998, 500))
22.7 usec: itemgetter(87, 342, 217, 998, 500)(myBigList)
24.6 usec: list( myBigList[i] for i in [87, 342, 217, 998, 500] )
Note that in Python 3, the 1st was changed to be the same as ...
Is “double hashing” a password less secure than just hashing it once?
...o compute a hash for each password and see if it matches the stored hash.
All passwords are not equally likely. Attackers might exhaustively search all short passwords, but they know that their chances for brute-force success drop sharply with each additional character. Instead, they use an ordered...
How to read a file in reverse order?
...A correct, efficient answer written as a generator.
import os
def reverse_readline(filename, buf_size=8192):
"""A generator that returns the lines of a file in reverse order"""
with open(filename) as fh:
segment = None
offset = 0
fh.seek(0, os.SEEK_END)
file...
Replacing a fragment with another fragment inside activity group
...need to replace a fragment with another, you should have added them dynamically, first of all.
Note: R.id.fragment_container is a layout or container of your choice in the activity you are bringing the fragment to.
// Create new fragment and transaction
Fragment newFragment = new ExampleFragment(...
What is 'Pattern Matching' in functional languages?
...wesome.
Algebraic data types in a nutshell
ML-like functional languages allow you define simple data types called "disjoint unions" or "algebraic data types". These data structures are simple containers, and can be recursively defined. For example:
type 'a list =
| Nil
| Cons of 'a * 'a ...
How to start new activity on button click
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Yeah, easy lol. There is more codemissing than code actually typed. Where is all xml interface and .java code missing? Downvote
– Liquid Core
Jun 21 '15 at 12:50
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