return (function()
local builders = {}
local function register(name, f)
builders[name] = f
end
register('llpeg', function() return require [[Module:User:Cscott/llpeg]] end)
register('pqueue', function(myrequire)
--[[ Priority Queue implemented in lua, based on a binary heap.
Copyright (C) 2017 Lucas de Morais Siqueira <lucas.morais.siqueira@gmail.com>
License: zlib
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgement in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
]]--
-- modified by xxopxe@gmail.com
local floor = math.floor
local PriorityQueue = {}
PriorityQueue.__index = PriorityQueue
setmetatable(
PriorityQueue,
{
__call = function ()
local new = {}
setmetatable(new, PriorityQueue)
new:initialize()
return new
end
}
)
function PriorityQueue:initialize()
--[[ Initialization.
Example:
PriorityQueue = require "priority_queue"
pq = PriorityQueue()
]]--
self.heap_val = {}
self.heap_pri = {}
self.current_size = 0
end
function PriorityQueue:empty()
return self.current_size == 0
end
function PriorityQueue:size()
return self.current_size
end
function PriorityQueue:swim()
-- Swim up on the tree and fix the order heap property.
local heap_val = self.heap_val
local heap_pri = self.heap_pri
local floor = floor
local i = self.current_size
while floor(i / 2) > 0 do
local half = floor(i / 2)
if heap_pri[i] < heap_pri[half] then
heap_val[i], heap_val[half] = heap_val[half], heap_val[i]
heap_pri[i], heap_pri[half] = heap_pri[half], heap_pri[i]
end
i = half
end
end
function PriorityQueue:put(v, p)
--[[ Put an item on the queue.
Args:
v: the item to be stored
p(number): the priority of the item
]]--
--
self.current_size = self.current_size + 1
self.heap_val[self.current_size] = v
self.heap_pri[self.current_size] = p
self:swim()
end
function PriorityQueue:sink()
-- Sink down on the tree and fix the order heap property.
local size = self.current_size
local heap_val = self.heap_val
local heap_pri = self.heap_pri
local i = 1
while (i * 2) <= size do
local mc = self:min_child(i)
if heap_pri[i] > heap_pri[mc] then
heap_val[i], heap_val[mc] = heap_val[mc], heap_val[i]
heap_pri[i], heap_pri[mc] = heap_pri[mc], heap_pri[i]
end
i = mc
end
end
function PriorityQueue:min_child(i)
if (i * 2) + 1 > self.current_size then
return i * 2
else
if self.heap_pri[i * 2] < self.heap_pri[i * 2 + 1] then
return i * 2
else
return i * 2 + 1
end
end
end
function PriorityQueue:pop()
-- Remove and return the top priority item
local heap_val = self.heap_val
local heap_pri = self.heap_pri
local retval, retprio = heap_val[1], heap_pri[1]
heap_val[1], heap_pri[1] = heap_val[self.current_size], heap_pri[self.current_size]
heap_val[self.current_size], heap_pri[self.current_size] = nil, nil
self.current_size = self.current_size - 1
self:sink()
return retval, retprio
end
function PriorityQueue:peek()
-- return the top priority item
return self.heap_val[1], self.heap_pri[1]
end
return PriorityQueue
end)
register('day11', function(myrequire)
--[[ DAY 11 ]]--
local l = myrequire('llpeg')
local PriorityQueue = myrequire('pqueue')
--[[ PARSING ]]--
local Parsec = {}
Parsec.__index = Parsec
function Parsec:new(args)
return setmetatable(args, self)
end
function Parsec:__tostring()
if self.galaxy then
if self.id == nil then return "#" end
if self.id < 10 then return tostring(self.id) end
if self.id < 36 then return string.char(65 + self.id - 10) end
return "#" -- ran out of labels
end
return "."
end
local nl = l.P"\n"
function make_parsec(s)
if s == "#" then return Parsec:new{galaxy=true, xlen=1, ylen=1} end
return Parsec:new{xlen=1, ylen=1}
end
local patt = l.P{
"Graph",
Graph = l.Ct( l.V"Row" * (nl^1 * l.V"Row")^0 * nl^0) * -1,
Row = l.Ct( l.V"Parsec"^1 ),
Parsec = l.S"#." / make_parsec,
}
local Graph = {}
Graph.__index = Graph
function parse(source)
--print(inspect(source))
local ast, errlabel, pos = patt:match(source)
if not ast then
error(string.format("Error at pos %s label '%s'", pos, errlabel))
end
--print('Parsed with success!')
--print(inspect(ast))
return Graph:new(ast)
end
--[[ Part 1 ]]--
function Graph:new(data)
return setmetatable({ data=data }, self)
end
function Graph:at(row,col,default)
return (self.data[row] or {})[col] or default
end
function Graph:set(row,col,val)
if self.data == nil then
self.data = {}
end
if self.data[row] == nil then
self.data[row] = {}
end
self.data[row][col] = val
end
function Graph:rowN()
return #(self.data)
end
function Graph:colN()
return #(self.data[1])
end
function Graph:print()
for r,row in ipairs(self.data) do
for c,val in ipairs(row) do
if val == nil then val = " " end
io.write(tostring(val))
end
io.write("\n")
end
end
function Graph:number()
local galaxies = {}
local num = 1
for r,row in ipairs(self.data) do
for c,sp in ipairs(row) do
if sp.galaxy then
sp.id = num
num = num + 1
table.insert(galaxies, sp)
end
end
end
return galaxies
end
function Graph:expand(amt)
if amt == nil then amt = 2 end
-- first rows
for r=1,self:rowN() do
local saw_galaxy = false
for c=1,self:colN() do
if self:at(r, c).galaxy then saw_galaxy = true break end
end
if not saw_galaxy then
-- if we didn't see a galaxy, expand space
for c = 1,self:colN() do
self.data[r][c].ylen = amt
end
end
end
-- now columns
for c=1,self:colN() do
local saw_galaxy = false
for r=1,self:rowN() do
if self:at(r, c).galaxy then saw_galaxy = true break end
end
if not saw_galaxy then
-- if we didn't see a galaxy, expand space
for r=1,self:rowN() do
self.data[r][c].xlen = amt
end
end
end
end
function Graph:link()
for r=1,self:rowN() do
for c=1,self:colN() do
local sp = self:at(r,c)
sp.r, sp.c = r,c
if r > 1 then sp.n = self:at(r-1,c) end
if c > 1 then sp.w = self:at(r,c-1) end
if r < self:rowN() then sp.s = self:at(r+1,c) end
if c < self:colN() then sp.e = self:at(r,c+1) end
end
end
end
function Graph:number_nodes()
-- number all nodes
local V = {}
for r=1,self:rowN() do
for c=1,self:colN() do
local sp = self:at(r,c)
table.insert(V, sp)
sp.v = #V
end
end
return V
end
-- Dijkstra algorithm
function Graph:shortest_path_from_node(V, galaxies, galaxy_num)
local dist = {}
local prev = {}
local Q = PriorityQueue()
local seen = {}
dist[galaxies[galaxy_num].v] = 0
Q:put(galaxies[galaxy_num], 0)
while not Q:empty() do
local u = Q:pop()
seen[u.v] = true
local neighbor = function(neigh, weight)
if neigh == nil then return end
if seen[neigh.v] then return end
local alt = dist[u.v] + weight
if dist[neigh.v] == nil or alt < dist[neigh.v] then
dist[neigh.v] = alt
prev[neigh.v] = u
Q:put(neigh, dist[neigh.v])
end
end
neighbor(u.n, u.ylen)
neighbor(u.s, u.ylen)
neighbor(u.e, u.xlen)
neighbor(u.w, u.xlen)
end
local sum = 0
for g=1,#galaxies do
local gdist = dist[galaxies[g].v]
-- print(string.format("Between galaxy %d and galaxy %d: %d", galaxy_num, g,gdist))
sum = sum + gdist
end
return sum
end
-- Floyd-Warshall algorithm
function Graph:all_pairs_shortest_path(V, galaxies)
-- let dist be a |V| x |V| array of minimum distances initialzed to
-- infinity (which we'll represent as 'nil')
local dist = {}
for i=1,#V do
table.insert(dist, {})
end
-- initialize with edge weights
for r=1,self:rowN() do
for c=1,self:colN() do
local sp = self:at(r,c)
-- dist[v][v] = 0
dist[sp.v][sp.v] = 0
if sp.n ~= nil then dist[sp.v][sp.n.v] = sp.ylen end
if sp.s ~= nil then dist[sp.v][sp.s.v] = sp.ylen end
if sp.e ~= nil then dist[sp.v][sp.e.v] = sp.xlen end
if sp.w ~= nil then dist[sp.v][sp.w.v] = sp.xlen end
end
end
-- ok, the big O(N^3) step
for k=1,#V do
for i = 1,#V do
for j = 1,#V do
-- if distances are nil they are infinity
if dist[i][k] ~= nil and dist[k][j] ~= nil then
if dist[i][j] == nil or
dist[i][j] > (dist[i][k] + dist[k][j]) then
dist[i][j] = dist[i][k] + dist[k][j]
end
end
end
end
end
-- ok, all pairs shortest paths!
local sum = 0
for i=1,#galaxies do
for j=i+1,#galaxies do
local iv = galaxies[i].v
local jv = galaxies[j].v
local dist = dist[iv][jv]
sum = sum + dist
-- print(string.format("Between galaxy %d and galaxy %d: %d", i, j, dist))
end
end
return sum
end
function part12(source, amt)
local graph = parse(source)
--graph:print()
graph:expand(amt)
local galaxies = graph:number()
graph:link()
-- graph:print()
-- print(graph:rowN(),'x',graph:colN())
local V = graph:number_nodes()
--return graph:all_pairs_shortest_path(V, galaxies)
local sum = 0
for g=1,#galaxies do
sum = sum + graph:shortest_path_from_node(V, galaxies, g)
end
-- we double counted each pair, so:
return math.floor(sum/2)
end
function part1(source) return part12(source, 2) end
function part2(source, amt) return part12(source, amt) end
--[[ CLI:
local source = io.input("day11.input"):read("a")
print('Sum:', part1(source))
print('Sum:', part2(source, 1000000))
]]--
return {
part1 = function(frame)
local s = mw.title.new(frame.args[1]):getContent()
return part1(s)
end,
part2 = function(frame)
local s = mw.title.new(frame.args[1]):getContent()
return part2(s, tonumber(frame.args[2]))
end,
}
end)
local modules = {}
modules['table'] = require('table')
modules['string'] = require('string')
modules['strict'] = {}
local function myrequire(name)
if modules[name] == nil then
modules[name] = true
modules[name] = (builders[name])(myrequire)
end
return modules[name]
end
return myrequire('day11')
end)()
