大约有 46,000 项符合查询结果（耗时：0.0592秒） [XML]
What's with 181783497276652981 and 8682522807148012 in Random (Java 7)?
Why were 181783497276652981 and 8682522807148012 chosen in Random.java ?
3 Answers
...
Unique (non-repeating) random numbers in O(1)?
I'd like to generate unique random numbers between 0 and 1000 that never repeat (i.e. 6 doesn't show up twice), but that doesn't resort to something like an O(N) search of previous values to do it. Is this possible?
...
How to create an array containing 1…N
...is what you're looking for, why do you need an array? A simple var n = 45; and then looping from 1..n would do.
– casablanca
Sep 19 '10 at 18:33
3
...
How does numpy.histogram() work?
...ere are 3 bins, for values ranging from 0 to 1 (excl 1.), 1 to 2 (excl. 2) and 2 to 3 (incl. 3), respectively. The way Numpy defines these bins if by giving a list of delimiters ([0, 1, 2, 3]) in this example, although it also returns the bins in the results, since it can choose them automatically f...
CSS transition shorthand with multiple properties?
I can't seem to find the correct syntax for the CSS transition shorthand with multiple properties. This doesn't do anything:
...
Global access to Rake DSL methods is deprecated
I am working through the Ruby on Rails 3 tutorial book and typed the following on the command line:
5 Answers
...
What is the most efficient/elegant way to parse a flat table into a tree?
..., we can say that all popular SQL databases support recursive queries in standard syntax.
WITH RECURSIVE MyTree AS (
SELECT * FROM MyTable WHERE ParentId IS NULL
UNION ALL
SELECT m.* FROM MyTABLE AS m JOIN MyTree AS t ON m.ParentId = t.Id
)
SELECT * FROM MyTree;
I tested recursive que...
ObservableCollection not noticing when Item in it changes (even with INotifyPropertyChanged)
...
Doesn't this all depend on your understanding of the term changed? This could mean that a property of one of the elements in the collection has changed (which is how I think you are interpreting it) or it could mean that one of the elements of the collection has b...
Java 8: performance of Streams vs Collections
... the middle of the list using iterator.
Stop writing benchmarking code by hand, use JMH.
Proper benchmarks:
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@BenchmarkMode(Mode.AverageTime)
@OperationsPerInvocation(StreamVsVanilla.N)
public class StreamVsVanilla {
public static final int N = 10000;
...
Which, if any, C++ compilers do tail-recursion optimization?
...t it would work perfectly well to do tail-recursion optimization in both C and C++, yet while debugging I never seem to see a frame stack that indicates this optimization. That is kind of good, because the stack tells me how deep the recursion is. However, the optimization would be kind of nice as w...