src/random.js
function random (arg, used) {
	var n;

	do {
		n = Math.floor(Math.random() * arg);
	} while (used[n]);

	used[n] = 1;

	return n;
}
function random (arg, used) {
	var n;

	do {
		n = Math.floor(Math.random() * arg);
	} while (used[n]);

	used[n] = 1;

	return n;
}
function random ( arg , used ) { var n ; do { n = Math . floor ( Math . random ( ) * arg ) ; } while ( used [ n ] ) ; used [ n ] = 1 ; return n ; }
Generates a random number between 0 & ceiling

@method random
@param  {Number} arg  Ceiling
@param  {Object} used Hash of used indices
@return {Number}      Random number between 0 and ceiling
Generates a random number between 0 & ceiling