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Does the C++ standard mandate poor performance for iostreams, or am I just dealing with a poor imple
...ostreams to OS-specific I/O APIs and custom buffer management does give an order of magnitude improvement.
4 Answers
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Algorithm to generate all possible permutations of a list?
Say I have a list of n elements, I know there are n! possible ways to order these elements. What is an algorithm to generate all possible orderings of this list? Example, I have list [a, b, c]. The algorithm would return [[a, b, c], [a, c, b,], [b, a, c], [b, c, a], [c, a, b], [c, b, a]].
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Spring Java Config: how do you create a prototype-scoped @Bean with runtime arguments?
...figuration
public class ServiceConfig {
// only here to demo execution order
private int count = 1;
@Bean
@Scope(value = "prototype")
public TransferService myFirstService(String param) {
System.out.println("value of count:" + count++);
return new TransferServiceIm...
Accessing dict_keys element by index in Python3
...rted(dict) would do the exact same thing; produce a list of keys in sorted order. list(dict) will give you the list in dictionary order.
– Martijn Pieters♦
May 9 '18 at 16:11
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Simple proof that GUID is not unique [closed]
...On sale, $0.01 per 1k GUIDs. I'll throw in some bamboo wind chimes if you order in the next 60 minutes.
– ctacke
Nov 10 '09 at 5:31
7
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if/else in a list comprehension
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You can totally do that. It's just an ordering issue:
[unicode(x.strip()) if x is not None else '' for x in row]
In general,
[f(x) if condition else g(x) for x in sequence]
And, for list comprehensions with if conditions only,
[f(x) for x in sequence if co...
Compare two files line by line and generate the difference in another file
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What does "sorted" mean? That the lines have the same order? Then it's probably fine for most use cases - as in, checking for what lines have been added by comparing with a backed-up older version. If newly added lines cannot be between the existing lines, that's more of an issu...
Java Regex Capturing Groups
...d since it's any character, it'll match as many characters as there are in order to fulfill the condition for the next groups).
In short, your 1st group .* matches anything as long as the next group \\d+ can match something (in this case, the last digit).
As per the 3rd group, it will match anyt...
What is Linux’s native GUI API?
...ystem will also have an entire "stack" of other software running on it, in order to provide a graphical user interface and other features. Each element of this stack will offer its own API.
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CMake: How to build external projects and include their targets
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