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ROW_NUMBER() in MySQL
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107
I want the row with the single highest col3 for each (col1, col2) pair.
That's a groupwis...
How to swap keys and values in a hash
...was inverted (in essence, by letting you access keys through values):
{a: 1, b: 2, c: 3}.key(1)
=> :a
If you want to keep the inverted hash, then Hash#invert should work for most situations:
{a: 1, b: 2, c: 3}.invert
=> {1=>:a, 2=>:b, 3=>:c}
BUT...
If you have duplicate values,...
How can I sort a dictionary by key?
What would be a nice way to go from {2:3, 1:89, 4:5, 3:0} to {1:89, 2:3, 3:0, 4:5} ?
I checked some posts but they all use the "sorted" operator that returns tuples.
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Can we have functions inside functions in C++?
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12 Answers
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What does the “|” (single pipe) do in JavaScript?
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159
This is a bitwise or.
Since bitwise operations only make sense on integers, 0.5 is truncated.
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Mod in Java produces negative numbers [duplicate]
When I calculate int i = -1 % 2 I get -1 in Java. In Python, I get 1 as the result of -1 % 2 .
What do I have to do to get the same behavior in Java with the modulo function?
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Is it possible to use argsort in descending order?
...ail of the argsort to find the n highest elements:
avgDists.argsort()[::-1][:n]
Both methods are O(n log n) in time complexity, because the argsort call is the dominant term here. But the second approach has a nice advantage: it replaces an O(n) negation of the array with an O(1) slice. If you...
Does JavaScript have a method like “range()” to generate a range within the supplied bounds?
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Get the last non-empty cell in a column in Google Sheets
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16 Answers
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How to know if two arrays have the same values
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function arraysEqual(_arr1, _arr2) {
if (!Array.isArray(_arr1) || ! Array.isArray(_arr2) || _arr1.length !== _arr2.length)
return false;
var arr1 = _arr1.concat().sort();
var arr2 = _arr2.concat().sort();
for (var i = 0; i &l...