package
{
	import kwm.*;

	public class Diamond{

		public static const COLOR_WHITE:uint = 0xffffff;
		public static const COLOR_BLACK:uint = 0x000000;

		public static function main(): void
		{
			var r:uint;				//Größe des Radius
			var n:uint;				//Anzahl der Facetten (farbig abwechselnde Flächen)
			var s:uint;				//Anzahl der Segmente ("Spalten")
			var centerX:uint = 0;	//Mittelpunkt auf x-Achse
			var centerY:uint;		//Mittelpunkt auf y-Achse
			var valid:Boolean = true;

			while(true){


				r = Input.readUint();

				if(Input.hasEnded()){
					break;
				}

				if(!Input.isOkay()){
					valid = false;
					Input.clearError();
				}
				else if(r== 0){
					valid = false;
				}



				n = Input.readUint();

				if(Input.hasEnded()){
					break;
				}

				if(!Input.isOkay()){
					valid = false;
					Input.clearError();
				}

				else if(n < 4 || n%2 !=0){
					valid = false;
				}


				s = Input.readUint();

				if(Input.hasEnded()){
					break;
				}

				if(!Input.isOkay()){
					valid = false;
					Input.clearError();
				}

				else if(s == 0){
				valid = false;
				}

				if(!valid){
					valid = true;
					continue;
				}

				centerY = r;
				centerX += r;

				//print diamond
				printDiamond(r, n, s, centerX, centerY);
				centerX += r;
			}
		}
		public static function printDiamond(r:uint, n:uint, s:uint,
					centerX:uint, centerY:uint):void{
			var length:Number = r;
			var color:uint = COLOR_BLACK;
			for(var i:uint = 0; i < s; i++){
				printCircle(centerX, centerY, length, n, color);
				if(color == COLOR_BLACK)
					color = COLOR_WHITE;
				else
					color = COLOR_BLACK;
				length -= (r/s);
			}
		}

		//liefert die x-Koordinate des Punktes, der sich vom Punkt (x,*)
		//aus gesehen im Abstand "radius" und Winkel "angle" befindet.

		public static function printCircle(centerX:uint, centerY:uint,
					length:Number, n:uint, color:uint):void{
			var angle:Number = 0;
			var curCircleX:Number = xCoordinate(centerX, length, angle);
			var curCircleY:Number = yCoordinate(centerY, length, angle);
			var newCircleX:Number;
			var newCircleY:Number;
			while(angle < 2*Math.PI){
				angle += 2*Math.PI/n;

			newCircleX = xCoordinate(centerX, length, angle);
			newCircleY = yCoordinate(centerY, length, angle);

			//print a triangle

			printTriangle(centerX, centerY, curCircleX, curCircleY,
				newCircleX, newCircleY, color);

			curCircleX = newCircleX;
			curCircleY = newCircleY;

			if(color == COLOR_BLACK)
				color = COLOR_WHITE;
			else
				color = COLOR_BLACK;
			}
		}

		public static function printTriangle(centerX:uint, centerY:uint,
					curCircleX:Number, curCircleY:Number,
					newCircleX:Number, newCircleY:Number, color: uint):void{
			Drawing.graphics.lineStyle(1, COLOR_BLACK);
			Drawing.graphics.beginFill(color);
			Drawing.graphics.moveTo(centerX, centerY);
			Drawing.graphics.lineTo(curCircleX, curCircleY);
			Drawing.graphics.lineTo(newCircleX, newCircleY);
			Drawing.graphics.lineTo(centerX, centerY);
			Drawing.graphics.endFill();
		}

		public static function xCoordinate (x:Number, r:Number, angle:Number): Number{
			return x+r*Math.cos(angle);
		}

		//liefert die y-Koordinate des Punktes, der sich vom Punkt (*,y)
		//aus gesehen im Abstand "radius" und Winkel "angle" befindet.

		public static function yCoordinate (y:Number, r:Number, angle:Number): Number{
			return y-r*Math.sin(angle);
		}
	}
}