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Mod of negative number is melting my brain
...
I always use my own mod function, defined as
int mod(int x, int m) {
return (x%m + m)%m;
}
Of course, if you're bothered about having two calls to the modulus operation, you could write it as
int mod(int x, int m) {
int r = x%m;
return r<0 ? r+m : r;
}
or varian...
What is the most pythonic way to check if an object is a number?
...from fractions import Fraction
... for n in [2, 2.0, Decimal('2.0'), complex(2, 0), Fraction(2, 1), '2']:
... print(f'{n!r:>14} {isinstance(n, Number)}')
2 True
2.0 True
Decimal('2.0') True
(2+0j) True
Fraction(2, 1) True
'2' False
This is, o...
What are the differences between concepts and template constraints?
...oustrup consider the following relationship:
Concepts = Constraints + Axioms
To quickly summarise their meanings:
Constraint - A predicate over statically evaluable properties of a type. Purely syntactic requirements. Not a domain abstraction.
Axioms - Semantic requirements of types that are...
Generating matplotlib graphs without a running X server [duplicate]
...b seems to require the $DISPLAY environment variable which means a running X server. Some web hosting services do not allow a running X server session. Is there a way to generate graphs using matplotlib without a running X server?
...
deque iterator not dereferencable 问题 - C/C++ - 清泛网 - 专注C/C++及内核技术
...>
#include <queue>
using namespace std;
int main()
{
queue<int> x;
for(int i = 0;i < 10;i++)
{
x.push(i+1);
}
while(!x.empty()) {
cout << x.front() << " ";
x.pop();
x.push(x.front());
x.pop();
}
cout << e...
Visual Assist X 关闭spell check的错误下划线 - 更多技术 - 清泛网 - 专注C/C++及内核技术
Visual Assist X 关闭spell check的错误下划线原因：在vs中使用Visual Assist X，在注释中有中文，经常会显示下划线，看起来很不爽。解决：如下图步骤：补充：参考：http: blog.csdn....原因：
在vs中使用 Visual Assist X，在注释中有中文，经...
Check that an email address is valid on iOS [duplicate]
... @"^[A-Z0-9a-z\\._%+-]+@([A-Za-z0-9-]+\\.)+[A-Za-z]{2,4}$";
NSString *laxString = @"^.+@([A-Za-z0-9-]+\\.)+[A-Za-z]{2}[A-Za-z]*$";
NSString *emailRegex = stricterFilter ? stricterFilterString : laxString;
NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailReg...
Counting the number of True Booleans in a Python List
...True)
2
This is actually more efficient than sum, as well as being more explicit about the intent, so there's no reason to use sum:
In [1]: import random
In [2]: x = [random.choice([True, False]) for i in range(100)]
In [3]: %timeit x.count(True)
970 ns ± 41.1 ns per loop (mean ± std. dev. of...
What's the difference between a proc and a lambda in Ruby?
...rguments passed to it. From ri Kernel#lambda:
Equivalent to Proc.new, except the resulting Proc objects check the number of parameters passed when called.
An example:
p = Proc.new {|a, b| puts a**2+b**2 } # => #<Proc:0x3c7d28@(irb):1>
p.call 1, 2 # => 5
p.call 1 # => NoMethodEr...
Convert tuple to list and back
...nswered May 6 '14 at 14:27
KhonixKhonix
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