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Code Golf - π day
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In dc: 88 and 93 93 94 96 102 105 129 138 141 chars
Just in case, I am using OpenBSD and some supposedly non-portable extensions at this point.
93 chars. This is based on same formula as FORTRAN solution (slightly different results t...
How can I see the current value of my $PATH variable on OS X?
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You need to use the command echo $PATH to display the PATH variable or you can just execute set or env to display all of your environment variables.
By typing $PATH you tried to run your PATH variable contents as a command name.
Bash displayed the...
How to use a variable for the key part of a map
...ivalent to ['a':1]. This can be confusing if you define a variable named a and that you want the value of to be the key in your map. If this is the case, then you must escape >the key by adding parenthesis..
– Michal Bernhard
Mar 2 '16 at 13:10
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Change one value based on another value in pandas
I'm trying to reprogram my Stata code into Python for speed improvements, and I was pointed in the direction of PANDAS. I am, however, having a hard time wrapping my head around how to process the data.
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Conditions for automatic generation of default/copy/move ctor and copy/move assignment operator?
... compiler typically auto generates a default constructor, copy constructor and assignment operator.
3 Answers
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Default initialization of std::array?
...zed (C++11 §8.5/11). That includes objects of type std::array<T, N> and T[N].
Be aware that there are types for which default initialization has no effect and leaves the object's value indeterminate: any non-class, non-array type (§8.5/6). Consequently, a default-initialized array of object...
Check if item is in an array / list
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@jdi, and that loop will run much faster than the one coded explicitly in Python, not to mention being easier to read.
– Mark Ransom
Jun 28 '12 at 19:44
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Why does the C# compiler not fault code where a static method calls an instance method?
...C# 7.3 (May 2018). In What's new in C# 7.3, the section Improved overload candidates, item 1, it is explained how the overload resolution rules have changed so that non-static overloads are discarded early. So the below answer (and this entire question) has mostly only historical interest by now!
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Select something that has more/less than x character
...e documentation:
http://www.techonthenet.com/oracle/functions/length.php
And here is the mySQL Documentation of Length(string):
http://dev.mysql.com/doc/refman/5.1/en/string-functions.html#function_length
For PostgreSQL, you can use length(string) or char_length(string). Here is the PostgreSQL d...
Best algorithm for detecting cycles in a directed graph [closed]
...grey (current node is visited but all reachable nodes are not yet visited) and black (all reachable nodes are visited along with the current one) color coding, if a grey node finds another grey node then we've a cycle. [Pretty much what we've in Cormen's algorithm book]. Wondering if 'Tarjan's algor...