大约有 47,000 项符合查询结果（耗时：0.0482秒） [XML]
Efficient Algorithm for Bit Reversal (from MSB->LSB to LSB->MSB) in C
...here):
unsigned int
reverse(register unsigned int x)
{
x = (((x & 0xaaaaaaaa) >> 1) | ((x & 0x55555555) << 1));
x = (((x & 0xcccccccc) >> 2) | ((x & 0x33333333) << 2));
x = (((x & 0xf0f0f0f0) >> 4) | ((x & 0x0f0f0f0f) << 4));
...
Django Server Error: port is already in use
...
A more simple solution just type sudo fuser -k 8000/tcp.
This should kill all the processes associated with port 8000.
EDIT:
For osx users you can use sudo lsof -t -i tcp:8000 | xargs kill -9
sha...
pandas: filter rows of DataFrame with operator chaining
... boolean index.
In [96]: df
Out[96]:
A B C D
a 1 4 9 1
b 4 5 0 2
c 5 5 1 0
d 1 3 9 6
In [99]: df[(df.A == 1) & (df.D == 6)]
Out[99]:
A B C D
d 1 3 9 6
If you want to chain methods, you can add your own mask method and use that one.
In [90]: def mask(df, key, ...
Finding sum of elements in Swift array
...d.
Swift 3 and Swift 4:
let multiples = [...]
let sum = multiples.reduce(0, +)
print("Sum of Array is : ", sum)
Swift 2:
let multiples = [...]
sum = multiples.reduce(0, combine: +)
Some more info:
This uses Array's reduce method (documentation here), which allows you to "reduce a collectio...
What is the difference between exit(0) and exit(1) in C?
Can anyone tell me? What is the difference between exit(0) and exit(1) in C language?
11 Answers
...
How can I quickly sum all numbers in a file?
...;
}
-e syntax OK
Just for giggles, I tried this with a file containing 1,000,000 numbers (in the range 0 - 9,999). On my Mac Pro, it returns virtually instantaneously. That's too bad, because I was hoping using mmap would be really fast, but it's just the same time:
use 5.010;
use File::Map qw(ma...
How do I do base64 encoding on iOS?
..., 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'
};
@implementation NSString (NSStringAdditions)
+ (NSString *) base64StringFromData: (NSData *)data length: (int)length {
unsigned long ixtext, lentext;
long ctr...
The $.param( ) inverse function in JavaScript / jQuery
...eparam
– Felipe Castro
Jan 8 '13 at 0:52
2
Unfortunately the github page hasn't seen any updates ...
Numpy: Divide each row by a vector element
...combined with broadcasting:
In [6]: data - vector[:,None]
Out[6]:
array([[0, 0, 0],
[0, 0, 0],
[0, 0, 0]])
In [7]: data / vector[:,None]
Out[7]:
array([[1, 1, 1],
[1, 1, 1],
[1, 1, 1]])
share
...
What does the “|” (single pipe) do in JavaScript?
Why does 0.5 | 0 return zero, but any integer (including negative) returns the input integer? What does the single pipe ("|") do?
...