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Regular vs Context Free Grammars
...ammar is either right or left linear, whereas context free grammar is basically any combination of terminals and non-terminals. Hence you can see that regular grammar is a subset of context-free grammar.
So for a palindrome for instance, is of the form,
S->ABA
A->something
B->something
...
How can I calculate the difference between two dates?
...
Not all days have 86400 seconds. For a trivial example that's fine but it's not a good idea in the real world. DST changes, leap seconds, etc can all mess with it. NSCalendar can tell you how many seconds are in a given day.
...
Generating a unique machine id
...yourself and hash it to an arbitrary length. See the PDF specification for all SMBIOS structures available.
To query the SMBIOS info from Windows you could use EnumSystemFirmwareEntries, EnumSystemFirmwareTables and GetSystemFirmwareTable.
IIRC, the "unique id" from the CPUID instruction is deprec...
Bulk package updates using Conda
...
You want conda update --all.
conda search --outdated will show outdated packages, and conda update --all will update them (note that the latter will not update you from Python 2 to Python 3, but the former will show Python as being outdated if you ...
Run MySQLDump without Locking Tables
...bles you can use the --single-transaction option:
--lock-tables, -l
Lock all tables before dumping them. The tables are locked with READ
LOCAL to allow concurrent inserts in the case of MyISAM tables. For
transactional tables such as InnoDB and BDB, --single-transaction is
a much better option, be...
SQL Server SELECT INTO @variable?
... In case if you aren't using the database type that the OP is using, not all support TOP 1 as Adrian mentioned. SQL Server / MS Access use TOP, MySQL uses LIMIT, and Oracle uses ROWNUM. See w3schools.com/sql/sql_top.asp for more information.
– Tyler
Jul 7 '17...
Find out HTTP method in PHP [duplicate]
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$_SERVER['REQUEST_METHOD']
See the docs. It will contain the request method upper-cased (i.e. 'GET', 'HEAD', 'POST', 'PUT').
share
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stdbool.h C99标准杂谈 - C/C++ - 清泛网 - 专注C/C++及内核技术
...布尔型的预定义宏：
#define true 1
#define false 0
#define bool _Bool
typdef int _Bool
但是很遗憾，Visual C++不支持C99，至少现在来看是没这个计划(参见http://en.wikipedia.org/wiki/C99)。所以stdbool.h就不能在vc里面用：
http://msdn.microsoft.com/en-us/l...
MFC Static透明背景色的实现、Static控件自绘、Static字体修改 - C/C++ - ...
...件自绘、Static字体修改第一种：pDC->SetBkMode(TRANSPARENT);afx_msg HBRUSH CtlColor(CDC* *pDC* , UINT *nCtlColor* );COLORREF m_crText;COLORREF m_...第一种：pDC->SetBkMode(TRANSPARENT);
afx_msg HBRUSH CtlColor(CDC* /*pDC*/, UINT /*nCtlColor*/);
COLORREF m_crText;
COLORREF m_crBk;...
VC IP地址控件（CIPAddressCtrl ）的自绘 - C/C++ - 清泛网 - 专注C/C++及内核技术
...：代码：.h#pragma once class CMyIPCtrl : public CIPAddressCtrl{DECLARE_DYNAMIC(CMyIPCtrl)public:CMyIPCtrl();virtua...先看效果图：
代码：
.h
#pragma once
class CMyIPCtrl : public CIPAddressCtrl
{
DECLARE_DYNAMIC(CMyIPCtrl)
public:
CMyIPCtrl();
virtual ~CMyIPCtrl();...