大约有 47,000 项符合查询结果（耗时：0.0539秒） [XML]
Concurrent vs serial queues in GCD
I'm struggling to fully understand the concurrent and serial queues in GCD. I have some issues and hoping someone can answer me clearly and at the point.
...
Can hash tables really be O(1)?
...
You have two variables here, m and n, where m is the length of the input and n is the number of items in the hash.
The O(1) lookup performance claim makes at least two assumptions:
Your objects can be equality compared in O(1) time.
There will be few ha...
Difference between method and function in Scala
...cification tell us. Chapter 3 (types) tell us about Function Types (3.2.9) and Method Types (3.3.1). Chapter 4 (basic declarations) speaks of Value Declaration and Definitions (4.1), Variable Declaration and Definitions (4.2) and Functions Declarations and Definitions (4.6). Chapter 6 (expressions) ...
How to list the size of each file and directory and sort by descending size in Bash?
...
Simply navigate to directory and run following command:
du -a --max-depth=1 | sort -n
OR add -h for human readable sizes and -r to print bigger directories/files first.
du -a -h --max-depth=1 | sort -hr
...
Why is GHC so large/big?
... have to decide up front whether you're going to link dynamically or not. And we need more changes (e.g. to Cabal and the package system, amongst other things) before this is really practical.
share
|
...
Too many 'if' statements?
... it's ugly, excessive or a number of other things. I've looked at formulas and attempted to write a few solutions, but I end up with a similar amount of statements.
...
How to calculate age (in years) based on Date of Birth and getDate()
...
There are issues with leap year/days and the following method, see the update below:
try this:
DECLARE @dob datetime
SET @dob='1992-01-09 00:00:00'
SELECT DATEDIFF(hour,@dob,GETDATE())/8766.0 AS AgeYearsDecimal
,CONVERT(int,ROUND(DATEDIFF(hour,@dob,GE...
Logical operators (“and”, “or”) in DOS batch
...
You can do and with nested conditions:
if %age% geq 2 (
if %age% leq 12 (
set class=child
)
)
or:
if %age% geq 2 if %age% leq 12 set class=child
You can do or with a separate variable:
set res=F
if %hour% leq 6 se...
What algorithm can be used for packing rectangles of different sizes into the smallest rectangle pos
...
The quick and dirty first pass solution is always a great one to start with, as a comparison if nothing else.
Greedy placement from large to small.
Put the largest rectangle remaining into your packed area. If it can't fit anywhere, ...
Is it better to call ToList() or ToArray() in LINQ queries?
...lare it. This is usually because I need to iterate over it multiple times and it is expensive to compute. For example:
16...