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How to create relationships in MySQL
...nnodb you can create it like this:
CREATE TABLE accounts(
account_id INT NOT NULL AUTO_INCREMENT,
customer_id INT( 4 ) NOT NULL ,
account_type ENUM( 'savings', 'credit' ) NOT NULL,
balance FLOAT( 9 ) NOT NULL,
PRIMARY KEY ( account_id ),
FOREIGN KEY (customer_id) REFERENCE...
How do I create 7-Zip archives with .NET?
... work with the archive and found this thread. ShaprZipLib is a misleading hint!
– Onsokumaru
Aug 3 '18 at 9:20
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show 7 more comments
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Access an arbitrary element in a dictionary in Python
...ction() results do not support indexing, this is why first of all we must convert it into a list and then we can use the index [0]
– Noki
May 24 '19 at 9:41
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How to find nth occurrence of character in a string?
...gUtils.ordinalIndexOf, otherwise, here's an implementation:
public static int ordinalIndexOf(String str, String substr, int n) {
int pos = str.indexOf(substr);
while (--n > 0 && pos != -1)
pos = str.indexOf(substr, pos + 1);
return pos;
}
This post has been rewrit...
Is it possible to declare two variables of different types in a for loop?
...b"}}; i < N; ++i, f += 1.5) {
// ...
}
The above will give you:
int i set to 1
double f set to 1.0
std::string s set to "ab"
Make sure to #include <tuple> for this kind of declaration.
You can specify the exact types inside the tuple by typing them all out as I have with the std:...
Reset C int array to zero : the fastest way?
Assuming that we have a T myarray[100] with T = int, unsigned int, long long int or unsigned long long int, what is the fastest way to reset all its content to zero (not only for initialization but to reset the content several times in my program)? Maybe with memset?
...
Set every cell in matrix to 0 if that row or column contains a 0
...res in the end. Maybe my 2nd pass can be made more efficient...
import pprint
m = [[1, 0, 1, 1, 0],
[0, 1, 1, 1, 0],
[1, 1, 1, 1, 1],
[1, 0, 1, 1, 1],
[1, 1, 1, 1, 1]]
N = len(m)
### pass 1
# 1 rst line/column
c = 1
for i in range(N):
c &= m[i][0]
l = 1
for i in r...
Shared-memory objects in multiprocessing
...ray_base = multiprocessing.RawArray(ctype, np.prod(dimensions))
# convert to numpy array vie ctypeslib
self.shared_arrays[self.cur] = np.ctypeslib.as_array(shared_array_base)
# do a reshape for correct dimensions
# Returns a masked array containing the s...
SparseArray vs HashMap
I can think of several reasons why HashMap s with integer keys are much better than SparseArray s:
7 Answers
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Boost.Asio的简单使用(Timer,Thread,Io_service类) - C/C++ - 清泛网 - 专注C/C++及内核技术
...类提供了访问I/O的功能.我们首先在main函数中声明它.
int main()
{
boost::asio::io_service io;
下一步我们声明boost::asio::deadline_timer对象.这个asio的核心类提供I/O的功能(这里更确切的说是定时功能),总是把一个io_service对象作为他的...