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Explain the use of a bit vector for determining if all characters are unique
...bits (flag). Each bit in your code states whether the character with bit's index was found in string or not. You could use bit vector for the same reason instead of int. There are two differences between them:
Size. int has fixed size, usually 4 bytes which means 8*4=32 bits (flags). Bit vector us...
Deleting an element from an array in PHP
... key.
unset()
Note that when you use unset() the array keys won't change/reindex. If you want to reindex the keys you can use \array_values() after unset() which will convert all keys to numerical enumerated keys starting from 0.
Code
<?php
$array = [0 => "a", 1 => "b", 2 => "c"];
...
Switch Git branch without files checkout
...herbranch
If you need to commit on this branch, you'll want to reset the index too otherwise you'll end up committing something based on the last checked out branch.
git reset
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Replace all elements of Python NumPy Array that are greater than some value
...e fastest and most concise way to do this is to use NumPy's built-in Fancy indexing. If you have an ndarray named arr, you can replace all elements >255 with a value x as follows:
arr[arr > 255] = x
I ran this on my machine with a 500 x 500 random matrix, replacing all values >0.5 with 5...
Is it faster to count down than it is to count up?
...n than to count up.
For example if you need to use a FOR loop and the loop index is not used somewhere (like printing a line of N * to the screen)
I mean that code like this:
...
load scripts asynchronously
... feature) when all the scripts where done loading I redirected the page to index2.html where index2.html uses the same libraries. Because browsers have a cache once the page redirects to index2.html, index2.html loads in less than a second because it has all it needs to load the page. In my index.h...
Reordering arrays
...
The syntax of Array.splice is:
yourArray.splice(index, howmany, element1, /*.....,*/ elementX);
Where:
index is the position in the array you want to start removing elements from
howmany is how many elements you want to remove from index
element1, ..., elementX are ele...
OPTION (RECOMPILE) is Always Faster; Why?
...ge and distribution of the types of values in various column on tables and indexes. This helps the query engine to develop a "Plan" of attack for how it will do the query, for example the type of method it will use to match keys between tables using a hash or looking through the entire set. You can ...
How do I clone a range of array elements to a new array?
...ike to create a new array containing all the elements from X that begin at index 3 and ends in index 7. Sure I can easily write a loop that will do it for me but I would like to keep my code as clean as possible. Is there a method in C# that can do it for me?
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How to group dataframe rows into list in pandas groupby?
...me: b, dtype: object
In [3]: df1 = df.groupby('a')['b'].apply(list).reset_index(name='new')
df1
Out[3]:
a new
0 A [1, 2]
1 B [5, 5, 4]
2 C [6]
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