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Explode PHP string by new line
...can use to make your code system independent, see this link to find useful and system independent directory constants.
Warning
These constants make your page system independent, but you might run into problems when moving from one system to another when you use the constants with data stored on an...
What would cause an algorithm to have O(log log n) complexity?
... 16
16 / 2 = 8
8 / 2 = 4
4 / 2 = 2
2 / 2 = 1
This process takes 16 steps, and it's also the case that 65,536 = 216.
But, if we take the square root at each level, we get
√65,536 = 256
√256 = 16
√16 = 4
√4 = 2
Notice that it only takes four steps to get all the way down to 2. Why is this?...
Javascript how to split newline
I'm using jquery, and I have a textarea. When I submit by my button I will alert each text separated by newline.
How to split my text when there is a newline?
...
How can I repeat a character in Bash?
...
You can use:
printf '=%.0s' {1..100}
How this works:
Bash expands {1..100} so the command becomes:
printf '=%.0s' 1 2 3 4 ... 100
I've set printf's format to =%.0s which means that it will always print a single = no matter what argument it is given. Therefore it prints 100 =s.
...
Moving average or running mean
...
UPD: more efficient solutions have been proposed by Alleo and jasaarim.
You can use np.convolve for that:
np.convolve(x, np.ones((N,))/N, mode='valid')
Explanation
The running mean is a case of the mathematical operation of convolution. For the running mean, you slide a win...
Is there a way to select sibling nodes?
...
Well... sure... just access the parent and then the children.
node.parentNode.childNodes[]
or... using jQuery:
$('#innerId').siblings()
Edit: Cletus as always is inspiring. I dug further. This is how jQuery gets siblings essentially:
function getChildren(...
Finding duplicates in O(n) time and O(1) space
...ns in O(N) time. A swap only occurs if there is an i such that A[i] != i, and each swap sets at least one element such that A[i] == i, where that wasn't true before. This means that the total number of swaps (and thus the total number of executions of the while loop body) is at most N-1.
The seco...
Fast permutation -> number -> permutation mapping algorithms
...you have n possibilities, so you can describe this with a number between 0 and n-1. For the position that the next element ends up at, you have n-1 remaining possibilities, so you can describe this with a number between 0 and n-2.
Et cetera until you have n numbers.
As an example for n = 5, consid...
Maximum number of characters using keystrokes A, Ctrl+A, Ctrl+C and Ctrl+V
.... Then we iterate through for i up to n, doing two things: pressing A once and pressing select all + copy followed by paste j times (actually j-i-1 below; note the trick here: the contents are still in the clipboard, so we can paste it multiple times without copying each time). We only have to consi...
Remove all line breaks from a long string of text
...er to input a string of text into the console, but the string is very long and includes many line breaks. How would I take the user's string and delete all line breaks to make it a single line of text. My method for acquiring the string is very simple.
...