大约有 40,000 项符合查询结果（耗时：0.0401秒） [XML]
Functional programming - is immutability expensive? [closed]
...’d like to clarify some points.
The “in-place” quicksort isn’t really in-place (and quicksort is not by definition in-place). It requires additional storage in the form of stack space for the recursive step, which is in the order of O(log n) in the best case, but O(n) in the worst case.
Im...
Pelican 3.3 pelican-quickstart error “ValueError: unknown locale: UTF-8”
...
You could try a solution posted here or here. Basically, add some lines to your ~/.bash_profile:
export LC_ALL=en_US.UTF-8
export LANG=en_US.UTF-8
There is an outstanding bug report related to this issue. It appears that Python makes some assumptions about the format of l...
Python initializing a list of lists [duplicate]
...
The problem is that they're all the same exact list in memory. When you use the [x]*n syntax, what you get is a list of n many x objects, but they're all references to the same object. They're not distinct instances, rather, just n references to the sam...
Javascript sort array by two fields
...iot proof - but doesn't seem necessary.
function getSortMethod(){
var _args = Array.prototype.slice.call(arguments);
return function(a, b){
for(var x in _args){
var ax = a[_args[x].substring(1)];
var bx = b[_args[x].substring(1)];
var cx;
...
Easiest way to convert int to string in C++
...icking up a discussion with @v.oddou a couple of years later, C++17 has finally delivered a way to do the originally macro-based type-agnostic solution (preserved below) without going through macro uglyness.
// variadic template
template < typename... Args >
std::string sstr( Args &&....
C/C++ check if one bit is set in, i.e. int variable
...if you want to hide bit manipulation, you can write a macro:
#define CHECK_BIT(var,pos) ((var) & (1<<(pos)))
and use it this way to check the nth bit from the right end:
CHECK_BIT(temp, n - 1)
In C++, you can use std::bitset.
...
How can I start PostgreSQL server on Mac OS X?
...
The Homebrew package manager includes launchctl plists to start automatically. For more information, run brew info postgres.
Start manually
pg_ctl -D /usr/local/var/postgres start
Stop manually
pg_ctl -D /usr/local/var/postgres stop
Start automatically
"To have launchd start postgresql now and res...
Can't find the 'libpq-fe.h header when trying to install pg gem
...on Rails 3.1 pre version. I like to use PostgreSQL, but the problem is installing the pg gem. It gives me the following error:
...
Converting JavaScript object with numeric keys into array
...
It's actually very straight forward with jQuery's $.map
var arr = $.map(obj, function(el) { return el });
FIDDLE
and almost as easy without jQuery as well, converting the keys to an array and then mapping back the values with Arra...
Setting different color for each series in scatter plot on matplotlib
...
I don't know what you mean by 'manually'. You can choose a colourmap and make a colour array easily enough:
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.cm as cm
x = np.arange(10)
ys = [i+x+(i*x)**2 for i in range(10)]
colors = cm.ra...