Project Euler 121

/**
 * Copyright uwi ( http://wonderfl.net/user/uwi )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/dZC1
 */

package {
    import flash.display.Sprite;
    import flash.text.TextField;
    import flash.utils.getTimer;
    // @see http://projecteuler.net/index.php?section=problems&id=121
    public class Euler121 extends Sprite {
        private var _tf : TextField;
  
        public function Euler121() {
            _tf = new TextField();
            _tf.width = 465;
            _tf.height = 465;
            addChild(_tf);
            
            var s : int = getTimer();
            _tf.appendText(solve().toString() + "\n");
            var g : int = getTimer();
            _tf.appendText((g - s).toString() + " ms\n");
        }
        
        private const N : int = 15;
        
        private function solve() : int
        {
            var CN : int = (1 << N) - 1;
            var NH : Number = N / 2;
            
            var ret : Number = 0;
            var i : int, j : int;
            for(var c : int = 0;c <= CN;c++){
                var ct : int = c;
                ct = ((ct >> 1) & 0x5555) + (ct & 0x5555);
                ct = ((ct >> 2) & 0x3333) + (ct & 0x3333);
                ct = ((ct >> 4) & 0x0f0f) + (ct & 0x0f0f);
                ct = ((ct >> 8) & 0x00ff) + (ct & 0x00ff);
                if(ct <= NH)continue;
                
                var mul : Number = 1;
                for(i = c, j = 0;j < N;i >>= 1, j++){
                    if((i & 1) == 0)mul *= (j + 1);
                }
                ret += mul;
            }
            
            var r : Number = 1;
            for(i = 1;i <= N;i++)r *= (i + 1);
            
            _tf.appendText("" + ret + "\n");
            _tf.appendText("" + r + "\n");
            return r / ret;
        }
    }
}