QuickSelect.js

Implementation of the QuickSelect algorithm in Java for top-k computations

npm install

``
npm install qselect
`

code sample

`JavaScript
var QuickSelect = require('qselect');

var array = [1,2,3,49,10,-1,-2]

// QuickSelect rearranges the values so that the k smallest values occur in the first k positions
// they are not necessarily in sorted order

var cmp = function(a,b){return a var topk = QuickSelect(array,2,cmp).slice(0,2);
// should return an array containing the two smallest (-1, -2)



var reversecmp = function(a,b){return a>b;};
var topk = QuickSelect(array,2,reversecmp).slice(0,2);
// should return an array containing the two largest (10, 49)
``

When calling QuickSelect on an array larger than k, the value at index k after calling QuickSelect acts
as a pivot. This means that no value with index less than k can be larger than the pivot, and no
value with index larger than k can be smaller than the pivot.

Credit

Inspired by a code sample from Anno Langen.