inital commitHEADmaster

1 files changed, 144 insertions, 0 deletions

diff --git a/22/1.lua b/22/1.lua
new file mode 100644
index 0000000..fd946bb
--- /dev/null
+++ b/22/1.lua
@@ -0,0 +1,144 @@
+require "ext"
+local parse_map = true
+local map = {}
+local row,col = 0,0
+local start
+local commands = {}
+local face_size = 
+for line in io.lines() do
+	row = row + 1
+	if line ~= "" and parse_map then
+		col = 0
+		for char in line:gmatch("(.)") do
+			col = col + 1
+			local locf = string.format("%d,%d",row,col)
+			if char == "." then
+				if start == nil then
+					start = locf
+				end
+				map[locf] = true
+			elseif char == "#" then
+				map[locf] = false
+			end --else, it's nil
+		end
+	elseif line == "" and parse_map then
+		parse_map = false
+	elseif not parse_map then
+		local ccursor = line
+		while ccursor ~= "" do
+			if ccursor:find("^%d") then
+				table.insert(commands,{type="walk",n=ccursor:match("^(%d+)")})
+				ccursor = ccursor:gsub("^(%d+)","")
+			elseif ccursor:find("^[LR]") then
+				table.insert(commands,{type="turn",n=ccursor:match("^([LR])")})
+				ccursor = ccursor:gsub("^[LR]","")
+			end
+		end
+	end
+end
+
+local directions = {
+	up = {-1, 0},
+	down = {1,0},
+	left = {0,-1},
+	right = {0,1}
+}
+local dirmap = {
+	[0] = {
+		name = "right",
+		R = 1,
+		L = 3
+	},
+	[1] = {
+		name = "down",
+		R = 2,
+		L = 0
+	},
+	[2] = {
+		name = "left",
+		R = 3,
+		L = 1
+	},
+	[3] = {
+		name = "up",
+		R = 0,
+		L = 2
+	}
+}
+
+local mem_loop = {}
+local function find_loop_loc(sloc, direction)
+	print("Finding loop location from",sloc,"dir",direction)
+	if mem_loop[sloc] and mem_loop[sloc][direction] then
+		return mem_loop[sloc][direction]
+	end
+	local srow, scol = sloc:match("(%d+),(%d+)")
+	local radd, cadd = -direction[1], -direction[2]
+	while map[string.format("%d,%d",srow,scol)] ~= nil do
+		print("Examining",string.format("%d,%d",srow,scol),"was not nil")
+		srow, scol = srow + radd, scol + cadd
+	end
+	print("Examining",string.format("%d,%d",srow,scol),"was nil")
+	local ret = string.format("%d,%d",srow + direction[1],scol + direction[2])
+	mem_loop[ret] = mem_loop[ret] or {}
+	mem_loop[ret][direction] = ret
+	print("Returning",ret)
+	return ret
+end
+print("map",map)
+print("commands",commands)
+local state = {
+	location = start,
+	direction = 0
+}
+print("Starting state:",state)
+
+local function open(location,direction)
+	local crow, ccol = state.location:match("(%d+),(%d+)")
+	local rrow, rcol = crow + direction[1], ccol + direction[2]
+	local rloc = string.format("%d,%d",rrow,rcol)
+	if map[rloc] then
+		return true, rloc
+	elseif map[rloc] == false then
+		return false
+	else
+		local loop_loc = find_loop_loc(location,direction)
+		assert(map[loop_loc] ~= nil)
+		if map[loop_loc] then
+			return true, loop_loc
+		else
+			return false
+		end
+	end
+end
+
+local function run(state, instructions)
+	local function walk(state,n)
+		for i = 1, n do
+			local dir = directions[dirmap[state.direction].name]
+			local isopen, newloc = open(state.location,dir)
+			if isopen then
+				print("Walked to",newloc)
+				state.location = newloc
+			else
+				break
+			end
+		end
+	end
+	local function turn(state,dir)
+		state.direction = dirmap[state.direction][dir]
+	end
+	while #instructions > 0 do
+		local ins = table.remove(instructions,1)
+		if ins.type == "walk" then
+			walk(state,ins.n)
+		elseif ins.type == "turn" then
+			turn(state,ins.n)
+		end
+	end
+end
+
+run(state,commands)
+print(state)
+local row, col = state.location:match("(%d+),(%d+)")
+print((row*1000) + (col * 4) + state.direction)