Contract 0xf20c9fa34847...8bec65676af7

// Submitted by EthereumHistory (ethereumhistory.com)
contract HexValidator
{
    function blockHexCoordsValid(int8 x, int8 y) constant returns (bool)
    {
    	if(-33 <= y && y <= 33)
    	{
    		if(y % 2 != 0 ) // odd
    		{
    			if(-50 <= x && x <= 49)
    				return true;
    			
    		}
    		else // even
    		{
    			if(-49 <= x && x <= 49)
    				return true;
    			
    		}	
    	}	
    	else
    	{	
    		uint8 absx;
			uint8 absy;
			if(x < 0)
				absx = uint8(x*-1);
			else
				absx = uint8(x);
			if(y < 0)
				absy = uint8(y*-1);
			else
				absy = uint8(y);
    		if((y >= 0 && x >= 0) || (y < 0 && x > 0)) // first or 4th quadrants
    		{
    			if(y % 2 != 0 ) // odd
    			{
    				if (((absx*2) + (absy*3)) <= 198)
    					return true;
    				
    			}	
    			else	// even
    			{
    				if ((((absx+1)*2) + ((absy-1)*3)) <= 198)
    					return true;
    				
    			}
    		}
    		else
    		{	
    			if(y % 2 == 0 ) // even
    			{
    				if (((absx*2) + (absy*3)) <= 198)
    					return true;
    				
    			}	
    			else	// odd
    			{
    				if ((((absx+1)*2) + ((absy-1)*3)) <= 198)
    					return true;
    				
    			}
    		}
    	}
    	return false;
    }

    function getUint8FromByte32(bytes32 _b32, uint8 byteindex) public constant returns(uint8) {
    	uint numdigits = 64;
    	uint buint = uint(_b32);
    	uint upperpowervar = 16 ** (numdigits - (byteindex*2)); 		// @i=0 upperpowervar=16**64 (SEE EXCEPTION BELOW), @i=1 upperpowervar=16**62, @i upperpowervar=16**60
    	uint lowerpowervar = 16 ** (numdigits - 2 - (byteindex*2));		// @i=0 upperpowervar=16**62, @i=1 upperpowervar=16**60, @i upperpowervar=16**58
    	uint postheadchop;
    	if(byteindex == 0)
    		postheadchop = buint; 								//for byteindex 0, buint is just the input number. 16^64 is out of uint range, so this exception has to be made.
    	else
    		postheadchop = buint % upperpowervar; 				// @i=0 _b32=a1b2c3d4... postheadchop=a1b2c3d4, @i=1 postheadchop=b2c3d4, @i=2 postheadchop=c3d4
    	uint remainder = postheadchop % lowerpowervar; 			// @i=0 remainder=b2c3d4, @i=1 remainder=c3d4, @i=2 remainder=d4
    	uint evenedout = postheadchop - remainder; 				// @i=0 evenedout=a1000000, @i=1 remainder=b20000, @i=2 remainder=c300
    	uint b = evenedout / lowerpowervar; 					// @i=0 b=a1 (to uint), @i=1 b=b2, @i=2 b=c3
    	return uint8(b);
    }
}