結果

問題 No.1094 木登り / Climbing tree
ユーザー 👑 obakyan
提出日時 2021-05-24 19:46:42
言語 Lua
(LuaJit 2.1.1734355927)
結果
AC  
実行時間 1,258 ms / 2,000 ms
コード長 3,415 bytes
コンパイル時間 187 ms
コンパイル使用メモリ 5,248 KB
実行使用メモリ 76,288 KB
最終ジャッジ日時 2024-11-08 07:18:52
合計ジャッジ時間 26,129 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge2
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 1
other AC * 26
権限があれば一括ダウンロードができます

ソースコード

diff # 

local mfl, mce = math.floor, math.ceil
local mmi, mma = math.min, math.max
local bls, brs = bit.lshift, bit.rshift
local SegTree = {}
SegTree.updateAll = function(self)
  for i = self.stagenum - 1, 1, -1 do
    local cnt = bls(1, i - 1)
    for j = 1, cnt do
      self.stage[i][j] = self.func(self.stage[i + 1][j * 2 - 1], self.stage[i + 1][j * 2])
    end
  end
end
SegTree.create = function(self, n, func, emptyvalue)
  self.func, self.emptyvalue = func, emptyvalue
  local stagenum, mul = 1, 1
  self.stage = {{}}
  while mul < n do
    mul, stagenum = mul * 2, stagenum + 1
    self.stage[stagenum] = {}
  end
  self.stagenum = stagenum
  self.left_stage = {}
  for i = 1, n do
    local sp, sz = 1, bls(1, stagenum - 1)
    while(i - 1) % sz ~= 0 do
      sp, sz = sp + 1, brs(sz, 1)
    end
    self.left_stage[i] = sp
  end
  self.sz_stage = {}
  local tmp, sp = 1, stagenum
  for i = 1, n do
    if tmp * 2 == i then tmp, sp = tmp * 2, sp - 1 end
    self.sz_stage[i] = sp
  end
  for i = 1, mul do self.stage[stagenum][i] = emptyvalue end
  self:updateAll()
end
SegTree.getRange = function(self, left, right)
  if left == right then return self.stage[self.stagenum][left] end
  local stagenum = self.stagenum
  local ret = self.emptyvalue
  while left <= right do
    local stage = mma(self.left_stage[left], self.sz_stage[right - left + 1])
    local sz = bls(1, stagenum - stage)
    ret = self.func(ret, self.stage[stage][1 + brs(left - 1, stagenum - stage)])
    left = left + sz
  end
  return ret
end
SegTree.update = function(self, idx)
  for i = self.stagenum - 1, 1, -1 do
    local dst = brs(idx + 1, 1)
    local rem = dst * 4 - 1 - idx
    self.stage[i][dst] = self.func(self.stage[i + 1][idx], self.stage[i + 1][rem])
    idx = dst
  end
end
SegTree.setValue = function(self, idx, value, silent)
  self.stage[self.stagenum][idx] = value
  if not silent then
    self:update(idx)
  end
end
SegTree.new = function(n, func, emptyvalue)
  local obj = {}
  setmetatable(obj, {__index = SegTree})
  obj:create(n, func, emptyvalue)
  return obj
end

local n = io.read("*n")
local edge = {}
local cost = {}
local asked = {}
local cpos = {}
local len = {}
local stpos = {}
local score = {}
for i = 1, n do
  edge[i] = {}
  cost[i] = {}
  asked[i] = false
  cpos[i] = 0
  len[i] = 0
  stpos[i] = 0
  score[i] = 0
end
len[n + 1] = 1000000007
for i = 1, n - 1 do
  local x, y = io.read("*n", "*n")
  local c = io.read("*n")
  table.insert(edge[x], y)
  table.insert(edge[y], x)
  table.insert(cost[x], c)
  table.insert(cost[y], c)
end
local st = SegTree.new(2 * n - 1, function(a, b) return len[a] < len[b] and a or b end, n + 1)

local tasks = {1}
local sti = 1
while 0 < #tasks do
  local src = tasks[#tasks]
  table.remove(tasks)
  asked[src] = true
  -- print(src, len[src])
  stpos[src] = sti
  st:setValue(sti, src, true)
  sti = sti + 1
  while cpos[src] < #edge[src] do
    cpos[src] = cpos[src] + 1
    local dst = edge[src][cpos[src]]
    if not asked[dst] then
      len[dst] = len[src] + 1
      score[dst] = score[src] + cost[src][cpos[src]]
      table.insert(tasks, src)
      table.insert(tasks, dst)
      break
    end
  end
end
st:updateAll()

local q = io.read("*n")
for iq = 1, q do
  local a, b = io.read("*n", "*n")
  local sta, stb = stpos[a], stpos[b]
  if stb < sta then sta, stb = stb, sta end
  local p = st:getRange(sta, stb)
  print(score[a] + score[b] - score[p] * 2)
end
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