Combinations calculator

by soulwire

JavaScript

function factoral( n ) {
    var o = n;
    while(--n) o *= n;
    return o;
}

var n = 26+10; // number of items in pool
var r = 4; // items to choose per key
var p = factoral(n)/factoral(n-r); // n!/(n-r)!

console.log( ~~p );