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How many characters can UTF-8 encode?
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136
UTF-8 does not use one byte all the time, it's 1 to 4 bytes.
The first 128 characters (US-A...
Fastest way to reset every value of std::vector to 0
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353
std::fill(v.begin(), v.end(), 0);
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PostgreSQL function for last inserted ID
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( tl;dr : goto option 3: INSERT with RETURNING )
Recall that in postgresql there is no "id" concept for tables, just sequences (which are typically but not necessarily used as default values for surrogate primary keys, with the SERIAL pseudo-type...
What does “abstract over” mean?
...or example, consider a program that takes the sum of the numbers 1, 2, and 3:
val sumOfOneTwoThree = 1 + 2 + 3
This program is not very interesting, since it's not very abstract. We can abstract over the numbers we're summing, by integrating all lists of numbers under a single symbol ns:
def sum...
How can I delete a query string parameter in JavaScript?
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edited Feb 1 '19 at 20:31
community wiki
7 r...
Generate array of all letters and digits
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or
('a'..'z').to_a + ('0'..'9').to_a # works in 1.8 and 1.9
or
(0...36).map{ |i| i.to_s 36 }
(the Integer#to_s method converts a number to a string representing it in a desired numeral system)
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How to install Boost on Ubuntu
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Anton GuryanovAnton Guryanov
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Converting a Pandas GroupBy output from Series to DataFrame
...attle 2 2
2 Mallory Portland 2 2
3 Mallory Seattle 1 1
Or something like:
In [36]: DataFrame({'count' : df1.groupby( [ "Name", "City"] ).size()}).reset_index()
Out[36]:
Name City count
0 Alice Seattle 1
1 ...
Maven 3 warnings about build.plugins.plugin.version
Since I updated to Maven 3 I get the following warning messages at each build :
7 Answers
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What is tail recursion?
...ple function that adds the first N natural numbers. (e.g. sum(5) = 1 + 2 + 3 + 4 + 5 = 15).
Here is a simple JavaScript implementation that uses recursion:
function recsum(x) {
if (x === 1) {
return x;
} else {
return x + recsum(x - 1);
}
}
If you called recsum(5), th...