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When should I use Kruskal as opposed to Prim (and vice versa)?
...c.
If you implement both Kruskal and Prim, in their optimal form : with a union find and a finbonacci heap respectively, then you will note how Kruskal is easy to implement compared to Prim.
Prim is harder with a fibonacci heap mainly because you have to maintain a book-keeping table to record the...
What's the right way to pass form element state to sibling/parent elements?
...ContextContainer = React.createContext(null);
const initialAppState = {
selected: "Nothing"
};
function App() {
// The app has a state variable and update handler
const [appState, updateAppState] = useState(initialAppState);
return (
<div>
<h1>Passing state between c...
MySQL Error 1215: Cannot add foreign key constraint
...the 4th point was my problem. It's kind of nasty - but I'm very very happy mysql did crash for that
– Sebas
Jun 16 '16 at 15:21
|
show 10 mo...
Bogus foreign key constraint fail
...Two possibilities:
There is a table within another schema ("database" in mysql terminology) which has a FK reference
The innodb internal data dictionary is out of sync with the mysql one.
You can see which table it was (one of them, anyway) by doing a "SHOW ENGINE INNODB STATUS" after the drop f...
Why does Java's hashCode() in String use 31 as a multiplier?
... for 31 since 33 is not a prime:
Of the remaining
four, I'd probably select P(31), as it's the cheapest to calculate on a RISC
machine (because 31 is the difference of two powers of two). P(33) is
similarly cheap to calculate, but it's performance is marginally worse, and
33 is composit...
An explicit value for the identity column in table can only be specified when a column list is used
...tead of
SET IDENTITY_INSERT archive_table ON;
INSERT INTO archive_table
SELECT *
FROM source_table;
SET IDENTITY_INSERT archive_table OFF;
you need to write
SET IDENTITY_INSERT archive_table ON;
INSERT INTO archive_table (field1, field2, ...)
SELECT field1, field2, ...
FROM source_table;...
Where to place the 'assets' folder in Android Studio?
...
Select the app folder and then:
File > New > folder > assets Folder ,
the default location is inside /main folder
share
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...
海量数据相似度计算之simhash和海明距离 - 大数据 & AI - 清泛网 - 专注C/C++及内核技术
...对于结果的分析。分析前我们需要对这些数据去除重复,如何选择和设 通过 采集系统 我们采集了大量文本数据,但是文本中有很多重复数据影响我们对于结果的分析。分析前我们需要对这些数据去除重复,如何选择和设计文...
MySQL: multiple tables or one table with many columns?
...
Recently I was faced with this same problem, because MySQL InnoDB tables have a relatively small length limit (~8000 bytes). In my problem table (data from very lengthy insurance forms, more than 100 columns) we have multiple varchar columns, all UTF8. So we easily filled the ~...
How should one use std::optional?
...
@Rapptz Line 256: union storage_t { unsigned char dummy_; T value_; ... } Line 289: struct optional_base { bool init_; storage_t<T> storage_; ... } How is that not "a T and a bool"? I completely agree the implementation is very tricky an...
