Project Euler #008

/**
 * Copyright hycro ( http://wonderfl.net/user/hycro )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/kYa0
 */

package {
    import flash.display.Sprite;
    import flash.text.TextField;
    
    public class ProjectEuler extends Sprite {
		private var _textField:TextField;
       
        public function ProjectEuler() {
        		initialize();
        		writeAnswer(new Problem008);
        }
        
        private function writeAnswer(problem:AbstructProblem):void {
        		var answer:String = problem.getAnswer();
        		 _textField.appendText(answer);
        }
        
        private function initialize():void {
        	    _textField = new TextField();
            _textField.width = stage.stageWidth;
            _textField.height = stage.stageHeight;
            addChild(_textField);
        }
    }
}

class AbstructProblem {
	final public function getAnswer():String {
		var answer:String;
		try {
			answer = solve().toString();
		} catch (err:Error) {
			answer = err.name + " : " + err.message;
		}
		return answer;
	}
	
	protected function solve():Number {
		throw new Error("unsolved");
	}
}

class Problem008 extends AbstructProblem {
	override protected function solve():Number {
		var answer:Number;
		var text:String = 
			"73167176531330624919225119674426574742355349194934" +
			"96983520312774506326239578318016984801869478851843" +
			"85861560789112949495459501737958331952853208805511" +
			"12540698747158523863050715693290963295227443043557" +
			"66896648950445244523161731856403098711121722383113" +
			"62229893423380308135336276614282806444486645238749" +
			"30358907296290491560440772390713810515859307960866" +
			"70172427121883998797908792274921901699720888093776" +
			"65727333001053367881220235421809751254540594752243" +
			"52584907711670556013604839586446706324415722155397" +
			"53697817977846174064955149290862569321978468622482" +
			"83972241375657056057490261407972968652414535100474" +
			"82166370484403199890008895243450658541227588666881" +
			"16427171479924442928230863465674813919123162824586" +
			"17866458359124566529476545682848912883142607690042" +
			"24219022671055626321111109370544217506941658960408" +
			"07198403850962455444362981230987879927244284909188" +
			"84580156166097919133875499200524063689912560717606" +
			"05886116467109405077541002256983155200055935729725" +
			"71636269561882670428252483600823257530420752963450";
		
		var sequence:Vector.<uint> = new Vector.<uint>();
		for (var i:uint = 0; i < text.length; i++) {
			sequence[i] = parseInt(text.charAt(i));
		}
		
		answer = 0;
		for (i = 0; i < sequence.length - 5; i++) {
			var mul:uint = sequence[i] * sequence[i+1] * sequence[i+2] * sequence[i+3] * sequence[i+4];
			if (answer < mul) {
				answer = mul;
			}
		}
		
		return answer;
	}
}

class Utils {
	// 整数値の桁数の取得
	static public function disits(n:Number, radix:uint=10):Number {
		var d:Number = 0;
		
		n = Math.abs(n);
		while (n / radix != 0) {
			n = Math.floor(n / radix);
			d++;
		}
		
		return d;
	}
	
	// 指定した桁の値を取得
	static public function numberAt(n:Number, digit:Number, radix:Number=10):Number {
		var number:Number;
		
		while (--digit) {
			n = Math.floor(n / radix);
		}
		
		return n % radix
	}
}