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What is the most efficient Java Collections library? [closed]
...-time compliant and have highly deterministic behavior (in the microsecond range). Furthermore (unlike the standard library), Javolution is RTSJ safe (no memory clash or memory leak when used with Java Real-Time extension).
Javolution's real-time collection classes (map, list, table and set) can be...
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...ow lacks a number of features or has defects, e.g. in typed arrays or HTTP range requests
Safari
limited
none
Safari (desktop and mobile) lacks a number of features or has defects, e.g. in typed arrays or HTTP range requests
IE9
limited
...
Simple proof that GUID is not unique [closed]
...ingless. GUID generation algorithms don't generate values over the entire range with equal probability. In fact IIRC the original algorithm used the MAC address of the generating PC + the current time as part of the result - which reduces the risk of collision with Guids generated on other PCs, bu...
Split comma-separated strings in a column into separate rows
... strings in a column into separate rows, as it was the fastest over a wide range of sizes:
s <- strsplit(v$director, ",", fixed=TRUE)
s <- data.frame(director=unlist(s), AB=rep(v$AB, lengths(s)))
Note that using fixed=TRUE has significant impact on timings.
Compared Methods:
met <- alist(...
How does the vim “write with sudo” trick work?
...ll see that the highlighted lines take the place of % as your substitution range.)
:w isn't updating your file
One confusing part of this trick is that you might think :w is modifying your file, but it isn't. If you opened and modified file1.txt, then ran :w file2.txt, it would be a "save as"; fil...
Swapping column values in MySQL
...z set c1 = c1 ^ c2, c2 = c1 ^ c2, c1 = c1 ^ c2;
ERROR 1264 (22003): Out of range value for column 'c1' at row 2
mysql> update z set c1 = c1 + c2, c2 = c1 - c2, c1 = c1 - c2;
ERROR 1264 (22003): Out of range value for column 'c1' at row 3
mysql> select * from z;
+------------+------------+
| c...
How do I check if a string contains another string in Objective-C?
...
NSString *string = @"hello bla bla";
if ([string rangeOfString:@"bla"].location == NSNotFound) {
NSLog(@"string does not contain bla");
} else {
NSLog(@"string contains bla!");
}
The key is noticing that rangeOfString: returns an NSRange struct, and the documentation ...
Why do I get an UnsupportedOperationException when trying to remove an element from a List?
... with random indices, it's better to generate enough random numbers in the range, and then traversing the List once with a listIterator(), calling remove() at appropriate indices. There are questions on stackoverflow on how to generate random but distinct numbers in a given range.
With this, your a...
Should I always use a parallel stream when possible?
...rayList , HashMap , HashSet , and ConcurrentHashMap instances; arrays; int ranges; and long ranges. What these data structures have in common is that they can all be accurately and cheaply split into subranges of any desired sizes, which makes it easy to divide work among parallel threads. The abstr...
How is set() implemented?
... they do take constant time to look up items: python -m timeit -s "s = set(range(10))" "5 in s" 10000000 loops, best of 3: 0.0642 usec per loop <--> python -m timeit -s "s = set(range(10000000))" "5 in s" 10000000 loops, best of 3: 0.0634 usec per loop ... and that's the largest set that doesn...