added day 13 solution

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diff --git a/2018/aoc2018-d13.py b/2018/aoc2018-d13.py
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+#advent of code 2018 

+#day 13

+#part 1 and part 2

+

+#I got it working the first time, but I was getting a wrong answer for actual input

+#turns out I made a mistake in calculations for the crossroads for turn-left and turn-right

+#i hastily scrambled a set of 2 equations for X and Y coordinates 

+#and it costed me time wasted on debugging 

+#for each round I was drawing the current layout of the map with a single cart 

+#I noticed that at crossroads it was doing a turn-left, straight, turn-left 

+#(instead of right for 3rd crossroads)

+#I followed my equations by *slowly* calculating them on paper 

+#and found out that I had wrong signs for Y coordinate

+#fun puzzle nonetheless

+#comment for part2

+#i had a bit of an issue with getting it working properly

+#at this moment, the part2 is calculated correctly, but part1 was off

+#I cleaned up the code a bit and managed to solve this, so both parts are in the same file

+

+f = open("input.txt",'r');

+Testing = False;

+#Testing = True;

+if Testing:

+	f.close();

+	f = open("testinput.txt",'r');

+	

+class trackpoint:

+	def __init__(self, sign, x, y):

+		self.sign = sign;

+		self.positionX = x;

+		self.positionY = y;

+	def __str__(self):

+		return self.sign;

+		

+class hline(trackpoint):

+	def __init__(self, sign, x, y):

+		trackpoint.__init__(self, sign, x, y);

+	def GiveSteps(self, cart_x, cart_y, cartid):

+		#left or right

+		x_next = self.positionX + (self.positionX - cart_x); 

+		y_next = self.positionY + (self.positionY - cart_y); 

+		return [x_next, y_next];	

+		

+class vline(trackpoint):

+	def __init__(self, sign, x, y):

+		trackpoint.__init__(self, sign, x, y);

+	def GiveSteps(self, cart_x, cart_y, cartid):

+		#up or down

+		x_next = self.positionX + (self.positionX - cart_x); 

+		y_next = self.positionY + (self.positionY - cart_y); 

+		return [x_next, y_next];

+		

+class turnleft(trackpoint):

+	def __init__(self, sign, x, y):

+		trackpoint.__init__(self, sign, x, y);

+	def GiveSteps(self, cart_x, cart_y, cartid):

+		x_next = self.positionX - (cart_y - self.positionY); 

+		y_next = self.positionY - (cart_x - self.positionX);

+		return [x_next, y_next];

+		

+class turnright(trackpoint):

+	def __init__(self, sign, x, y):

+		trackpoint.__init__(self, sign, x, y);

+	def GiveSteps(self, cart_x, cart_y, cartid):

+		x_next = self.positionX + (cart_y - self.positionY); 

+		y_next = self.positionY + (cart_x - self.positionX);

+		return [x_next, y_next];

+		

+class crossroads(trackpoint):

+	def __init__(self, sign, x, y):

+		trackpoint.__init__(self, sign, x, y);

+		self.CartRegistry = {};

+	def GiveSteps(self, cart_x, cart_y, cartid):

+		#number of crossroads is updated before this function is called, thats why it starts from 1

+		if (cartid%3 == 1):

+			#turn left

+			x_next = self.positionX - (cart_y - self.positionY); 

+			y_next = self.positionY + (cart_x - self.positionX); 

+		elif (cartid%3 == 2): 

+			#go straight 

+			x_next = self.positionX + (self.positionX - cart_x); 

+			y_next = self.positionY + (self.positionY - cart_y); 

+		elif (cartid%3 == 0): 

+			#turn right

+			x_next = self.positionX + (cart_y - self.positionY); 

+			y_next = self.positionY - (cart_x - self.positionX); 

+		return [x_next, y_next];

+

+class minecart: 

+	def __init__(self, sign, x, y, cart_id):

+		self.posX = x;

+		self.posY = y;

+		self.XroadsEncountered = 0;

+		self.nextstepX = x;

+		self.nextstepY = y;

+		self.Cart_ID = cart_id;

+		self.notHit = True;

+		if (sign == '>'):

+			self.prevX = x-1;

+			self.prevY = y;

+		if (sign == '<'):

+			self.prevX = x+1;

+			self.prevY = y;

+		if (sign == 'v'):

+			self.prevX = x;

+			self.prevY = y-1;

+		if (sign == '^'):

+			self.prevX = x;

+			self.prevY = y+1;

+	def cartmove(self, nextX, nextY):

+		self.nextstepX = nextX;

+		self.nextstepY = nextY;

+		self.prevX = self.posX;

+		self.prevY = self.posY;

+		self.posX = self.nextstepX;

+		self.posY = self.nextstepY;

+	def ReadCoords(self):

+		return [self.posX, self.posY];

+	def CheckMatch(self, OtherCoords):

+		return (self.posX == OtherCoords[0] and self.posY == OtherCoords[1]);

+	def IsXroads(self, currentsign):

+		if (currentsign == "+"):

+			self.XroadsEncountered += 1;

+

+trackmap = [];

+

+for l in f:

+	subline = [];

+	l.replace("\n", "");

+	for c in l:

+		subline.append(c);

+	trackmap.append(subline.copy());

+

+cartlist = [];

+cartid_counter = 10;

+

+TMSize_C = len(trackmap);

+TMSize_R = len(trackmap[0]) -1;

+#RETREIVING MINECARTS AND REPLACING SIGNS ON THE MAP

+for c in range(TMSize_C):

+	for r in range(TMSize_R):

+		if (trackmap[c][r] == '^' or trackmap[c][r] == 'v' or trackmap[c][r] == '>' or trackmap[c][r] == '<'):

+			cartlist.append( minecart(trackmap[c][r], r, c, cartid_counter) );

+			cartid_counter += 1;

+			if (trackmap[c][r] == '^' or trackmap[c][r] == 'v'):

+				trackmap[c][r] = '|';

+			if (trackmap[c][r] == '>' or trackmap[c][r] == '<'):

+				trackmap[c][r] = '-';

+

+cartlist = sorted(cartlist, key=lambda x: (x.posY, x.posX));

+newmap = [];

+

+for c in range(TMSize_C):

+	templine = [];

+	for r in range(TMSize_R):

+		if (trackmap[c][r] == ' '):

+			templine.append( trackpoint(trackmap[c][r], r, c) );

+		elif (trackmap[c][r] == '-'):

+			templine.append( hline(trackmap[c][r], r, c) );

+		elif (trackmap[c][r] == '|'):

+			templine.append( vline(trackmap[c][r], r, c) );

+		elif (trackmap[c][r] == '/'):

+			templine.append( turnright(trackmap[c][r], r, c) );

+		elif (trackmap[c][r] == '\\'):

+			templine.append( turnleft(trackmap[c][r], r, c) );

+		elif (trackmap[c][r] == '+'):

+			templine.append( crossroads(trackmap[c][r], r, c) );

+	newmap.append( templine.copy() );

+

+roundcounter = 0;

+part1 = None;

+p1round = 0;

+

+while (len(cartlist) > 1):

+	roundcounter += 1;

+	cartlist = sorted(cartlist, key=lambda x: (x.posY, x.posX));

+	for mc in cartlist:

+		NextSteps = [];

+		mc.IsXroads(newmap[mc.posY][mc.posX].sign);

+		NextSteps = newmap[mc.posY][mc.posX].GiveSteps(mc.prevX, mc.prevY, mc.XroadsEncountered);

+		mc.cartmove(NextSteps[0],NextSteps[1]);

+		MatchCounter = 0;

+		for mc2 in cartlist:

+			if mc.Cart_ID != mc2.Cart_ID:

+				mc.notHit  = not mc.CheckMatch( mc2.ReadCoords() );

+				mc2.notHit = not mc2.CheckMatch( mc.ReadCoords() );

+			if part1 == None and mc.notHit == False:

+				part1 = mc.ReadCoords();

+				p1round = int(roundcounter);

+				#print("part 1 = ",part1, "\t after", roundcounter, "rounds");

+			cartlist = [c for c in cartlist if c.notHit];

+

+part2 = cartlist[0].ReadCoords();

+print("part 1 = ",part1, "\t after", p1round, "rounds");

+print("part 2 = ",part2, "\t after", roundcounter, "rounds");