結果

問題 No.1332 Range Nearest Query
ユーザー 👑 obakyan
提出日時 2022-05-11 23:31:38
言語 Lua
(LuaJit 2.1.1734355927)
結果
AC  
実行時間 846 ms / 2,500 ms
コード長 4,928 bytes
コンパイル時間 163 ms
コンパイル使用メモリ 5,376 KB
実行使用メモリ 72,968 KB
最終ジャッジ日時 2024-07-19 09:30:22
合計ジャッジ時間 28,294 ms
ジャッジサーバーID
（参考情報） 		judge3 / 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
other AC * 48
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.right_bound = function(self, val, left, right)
  local ret, retpos = self.emptyvalue, left - 1
  local l, r = left, right
  local stage = mma(self.left_stage[left], self.sz_stage[right - left + 1])
  local stagenum = self.stagenum
  while true do
    local sz = bls(1, stagenum - stage)
    local tmp = self.func(ret, self.stage[stage][mce(l / sz)])
    if tmp < val then
      ret, retpos = tmp, l + sz - 1
      if retpos == right then break end
      if l + sz <= r then
        l = l + sz
        stage = mma(self.left_stage[l], self.sz_stage[r - l + 1])
      else break end
    else
      if sz ~= 1 then stage, r = stage + 1, l + sz - 2
      else break end
    end
  end
  return retpos + 1
end
SegTree.left_bound = function(self, val, left, right)
  local ret, retpos = self.emptyvalue, right + 1
  local stage, l, r = 1, left, right
  local stagenum = self.stagenum
  while true do
    local sz = bls(1, stagenum - stage)
    while r % sz ~= 0 or r + 1 - l < sz do
      stage = stage + 1
      sz = bls(1, stagenum - stage)
    end
    local tmp = self.func(ret, self.stage[stage][mfl(r / sz)])
    if tmp < val then
      ret, retpos = tmp, r - sz + 1
      if l + sz <= r then stage, l, r = 1, l, r - sz
      else break end
    else
      if sz ~= 1 then stage, l, r = stage + 1, r - sz + 2, r
      else break end
    end
  end
  return retpos - 1
end

SegTree.new = function(n, func, emptyvalue)
  local obj = {}
  setmetatable(obj, {__index = SegTree})
  obj:create(n, func, emptyvalue)
  return obj
end

local function comp(a, b)
  return a < b
end

local function lower_bound(ary, x)
  local num = #ary
  if num == 0 then return 1 end
  if not comp(ary[1], x) then return 1 end
  if comp(ary[num], x) then return num + 1 end
  local min, max = 1, num
  while 1 < max - min do
    local mid = mfl((min + max) / 2)
    if comp(ary[mid], x) then
      min = mid
    else
      max = mid
    end
  end
  return max
end

local n = io.read("*n")
local x = {}
local xuniq = {}
local tasks = {}
for i = 1, n do
  x[i] = io.read("*n")
  xuniq[i] = x[i]
  tasks[i] = {}
end
table.sort(xuniq)
local xmap = {}
for i = 1, n do
  xmap[xuniq[i]] = i
end
local q = io.read("*n")
local l, r, xq = {}, {}, {}
local ans = {}
local inf = 1000000007
for i = 1, q do
  l[i], r[i], xq[i] = io.read("*n", "*n", "*n")
  ans[i] = inf
  table.insert(tasks[r[i]], i)
end
local st = SegTree.new(n, mma, 0)
for i = 1, n do
  local xi = x[i]
  local xpos = xmap[xi]
  st:setValue(xpos, i)
  for j = 1, #tasks[i] do
    local iq = tasks[i][j]
    local li = l[iq]
    local xqi = xq[iq]
    local xqpos = lower_bound(xuniq, xqi)
    local ret = inf
    if 1 < xqpos then
      local left = st:left_bound(li, 1, xqpos - 1)
      if 1 <= left then
        ans[iq] = mmi(ans[iq], xqi - xuniq[left])
      end
    end
    if xqpos <= n then
      local right = st:right_bound(li, xqpos, n)
      if right <= n then
        ans[iq] = mmi(ans[iq], xuniq[right] - xqi)
      end
    end
  end
end
print(table.concat(ans, "\n"))
0