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Computational complexity of Fibonacci Sequence
I understand Big-O notation, but I don't know how to calculate it for many functions. In particular, I've been trying to figure out the computational complexity of the naive version of the Fibonacci sequence:
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Label encoding across multiple columns in scikit-learn
I'm trying to use scikit-learn's LabelEncoder to encode a pandas DataFrame of string labels. As the dataframe has many (50+) columns, I want to avoid creating a LabelEncoder object for each column; I'd rather just have one big LabelEncoder objects that works across all my columns of data. ...
Elastic Search: how to see the indexed data
I had a problem with ElasticSearch and Rails, where some data was not indexed properly because of attr_protected. Where does Elastic Search store the indexed data? It would be useful to check if the actual indexed data is wrong.
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(Deep) copying an array using jQuery [duplicate]
...an a value.
Likewise delete(b[0][0]) also causes a[0][0] to be deleted and b[0][0]=99 also changes the value of a[0][0] to 99.
jQuery's extend method does perform a deep copy when a true value is passed as the initial argument:
var a =[[1], [2], [3]];
var b = $.extend(true, [], a);
b.shift()....
Convert integer to binary in C#
...ger expressed as a string. Let's say your integer was actually an integer, and you want to take the integer and convert it to a binary string.
int value = 8;
string binary = Convert.ToString(value, 2);
Which returns 1000.
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Best way to merge two maps and sum the values of same key?
I want to merge them, and sum the values of same keys. So the result will be:
15 Answers
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How do I convert an object to an array?
...your properties are declared private you should call this inside the class and return its results.
Be careful, for primitive data types like strings it will work great, but I don't know how it behaves with nested objects.
in your case you have to do something like;
<?php
print_r(get_objec...
The cast to value type 'Int32' failed because the materialized value is null
...ky abstraction" that yields unexpected behaviour.
One such case is null handling, where there can be unexpected nulls in different places. ...DefaultIfEmpty(0).Sum(0) can help in this (quite simple) case, where there might be no elements and sql's SUM returns null whereas c# expect 0.
A more gene...
How do I overload the square-bracket operator in C#?
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+1 for the handy list. FYI the link died. (4 years later, I know)
– Mixxiphoid
Mar 4 '13 at 21:04
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How to get the HTML for a DOM element in javascript
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Expanding on jldupont's answer, you could create a wrapping element on the fly:
var target = document.getElementById('myElement');
var wrap = document.createElement('div');
wrap.appendChild(target.cloneNode(true));
alert(wrap.i...