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Why is inserting in the middle of a linked list O(1)?
...r business logic that a new node needs to be added (or an old one deleted) and you do so. You may add 50 nodes in a single iteration and each of those nodes is just O(1) the time to unlink two adjacent nodes and insert your new one..
Edit: Man, you type a second paragraph and all of a sudden inste...
How can one check to see if a remote file exists using PHP?
...y save the cost of the HTTP transfer, not the TCP connection establishment and closing. And being favicons small, you might not see much improvement.
Caching the result locally seems a good idea if it turns out to be too slow.
HEAD checks the time of the file, and returns it in the headers. You can...
Dynamically load a JavaScript file
How can you reliably and dynamically load a JavaScript file? This will can be used to implement a module or component that when 'initialized' the component will dynamically load all needed JavaScript library scripts on demand.
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.Contains() on a list of custom class objects
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You need to implement IEquatable or override Equals() and GetHashCode()
For example:
public class CartProduct : IEquatable<CartProduct>
{
public Int32 ID;
public String Name;
public Int32 Number;
public Decimal CurrentPrice;
public CartProduct(Int32 ...
Can a foreign key be NULL and/or duplicate?
...als. Suppose further that each proposal only has one sales person assigned and one client. So your proposal table would have two foreign keys, one with the client ID and one with the sales rep ID. However, at the time the record is created, a sales rep is not always assigned (because no one is fre...
How do I redirect in expressjs while passing some context?
...gs. You'll need to ensure that the values are properly encodeURIComponent and decodeURIComponent.
app.get('/category', function(req, res) {
var string = encodeURIComponent('something that would break');
res.redirect('/?valid=' + string);
});
You can snag that in your other route by getting t...
Find rows that have the same value on a column in MySQL
...
This query will give you a list of email addresses and how many times they're used, with the most used addresses first.
SELECT email,
count(*) AS c
FROM TABLE
GROUP BY email
HAVING c > 1
ORDER BY c DESC
If you want the full rows:
select * from table where email ...
Select DISTINCT individual columns in django?
...distinct(). The above example will work but all combinations of distinct() and values() may not.
PS: it is a good idea to use lower case names for fields in a model. In your case this would mean rewriting your model as shown below:
class ProductOrder(models.Model):
product = models.CharField...
Prevent the keyboard from displaying on activity start
...activity with an Edit Text input. When the activity is initialized, the Android keyboard is shown. How can the keyboard remain hidden until the user focuses the input?
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Best XML parser for Java [closed]
...most, UTF-8 encoded) XML files, rummage around looking at various elements and attributes, perhaps modify a few and write the XML back out again to disk (preferably with nice, indented formatting).
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