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+#advent of code 2018 
+#day 20
+#part 1 and part 2
+
+#I struggled with indexing when parsing the input
+#I was getting more doors mapped than there really were
+#the issue was that after parsing the content of a bracket
+#I was retreiving a ")" sign instead of the following instruction like N or W
+#+1 to the index did the work 
+#a bit disappointed with part 2, on which I spent more time reading it than coding
+
+f = open("input.txt",'r');
+Testing = False;
+#Testing = True; 
+if Testing:
+	f.close();
+	f = open("testinput.txt",'r');
+
+inputline = f.readline();
+inputline = inputline[1:-1];
+f.close();
+#split the contents of a bracket into separate strings, return a list of those strings
+def parse_brackets(regex):
+	regex = regex[1:];
+	close_brackets_sign = ")";
+	close_brackets_count = 1;
+	subsets = [];
+	subset = "";
+	for i, c in enumerate(regex):
+		if c == "(":
+			close_brackets_count += 1;
+			subset += c;
+		elif c == close_brackets_sign:
+			if close_brackets_count == 1:
+				subsets.append(subset);
+				break;
+			else:
+				close_brackets_count -= 1;
+				subset += c;
+		elif c == "|":
+			if close_brackets_count == 1:
+				subsets.append(subset);
+				subset = "";
+			else: subset += c;
+		else: subset += c;
+	return i, subsets;
+#fill up the "area" dictionary with rooms and doors based on provided instruction
+#recursive function, the function is called again if the path is branching due to brackets
+def parse_input(inputline, Cords, grid):
+	i = 0;
+	d = (0,0);
+	CurrentCords = Cords;
+	CurrentCords = (CurrentCords[0] +d[0],CurrentCords[1] +d[1]);
+	while i < len(inputline):
+		c = inputline[i];
+		if c == "(":
+			x, subs = parse_brackets(inputline[i:]);
+			for s in subs:
+				parse_input(s, CurrentCords, grid);
+			i += x+1;
+		elif c == "$":
+			break;
+		else:
+			if c == "N":
+				d = (0,-1);
+			elif c == "S":
+				d = (0,1);
+			elif c == "W":
+				d = (-1,0);
+			elif c == "E":
+				d = (1,0);
+			CurrentCords = (CurrentCords[0] +d[0],CurrentCords[1] +d[1]);
+			grid.update({CurrentCords:"D"});
+			CurrentCords = (CurrentCords[0] +d[0],CurrentCords[1] +d[1]);
+			grid.update({CurrentCords:"."});
+		i += 1;
+
+area = {};
+p = (0,0);
+area.update({p:"."});
+
+parse_input(inputline, p, area);
+#print the map of the area
+'''
+maxX = max([x[0] for x in area]);
+minX = min([x[0] for x in area]);
+maxY = max([y[1] for y in area]);
+minY = min([y[1] for y in area]);
+
+for y in range(minY-1, maxY+1+1):
+	for x in range(minX-1, maxX+1+1):
+		cp = area.get((x,y),"#");
+		if x==0 and y==0: cp = "X";
+		print(cp, end="");
+	print();
+'''
+
+distances = {};
+queue = [(0,0,0)];
+
+while queue:
+	x,y,d = queue.pop();
+	if ((x,y) in distances and distances.get((x,y)) <= d):
+		continue;
+	distances.update({(x,y):d});
+	if (x+1,y) in area and (x+2,y) in area: queue.append((x+2,y,d+1));
+	if (x-1,y) in area and (x-2,y) in area: queue.append((x-2,y,d+1));
+	if (x,y+1) in area and (x,y+2) in area: queue.append((x,y+2,d+1));
+	if (x,y-1) in area and (x,y-2) in area: queue.append((x,y-2,d+1));
+
+part1 = max([distances[dist] for dist in distances]);
+print("part1 = ", part1);
+
+part2 =len([distances[dist] for dist in distances if distances[dist]>=1000]);
+print("part2 = ", part2);