結果

問題 No.738 平らな農地
コンテスト
ユーザー 👑 obakyan
提出日時 2022-01-02 20:34:09
言語 Lua
(LuaJit 2.1.1734355927)
結果
AC  
実行時間 397 ms / 2,000 ms
コード長 3,849 bytes
コンパイル時間 120 ms
コンパイル使用メモリ 6,696 KB
実行使用メモリ 16,072 KB
最終ジャッジ日時 2024-10-12 00:25:32
合計ジャッジ時間 15,553 ms
ジャッジサーバーID
（参考情報） 		judge3 / judge5
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 * 5
other AC * 87
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.addValue = function(self, idx, value, silent)
  self.stage[self.stagenum][idx] = self.stage[self.stagenum][idx] + value
  if not silent then
    self:update(idx)
  end
end
SegTree.lower_bound = function(self, val)
  local ret, retpos = self.emptyvalue, 0
  local stagenum = self.stagenum
  local stage, l, r = 1, 1, bls(1, stagenum - 1)
  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 l + sz <= r then stage, l = stage + 1, l + sz
      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.new = function(n, func, emptyvalue)
  local obj = {}
  setmetatable(obj, {__index = SegTree})
  obj:create(n, func, emptyvalue)
  return obj
end

local n, k = io.read("*n", "*n")
local a = {}
local amap = {}
for i = 1, n do
  a[i] = io.read("*n")
  amap[a[i]] = true
end
if k == 1 then print(0) os.exit() end
local hk = mce(k / 2)
local auniq = {}
for p, q in pairs(amap) do
  table.insert(auniq, p)
end
table.sort(auniq)
local an = #auniq
for i = 1, an do
  amap[auniq[i]] = i
end
local stcnt = SegTree.new(an, function(x, y) return x + y end, 0)
local stval = SegTree.new(an, function(x, y) return x + y end, 0)
for i = 1, k do
  local val = a[i]
  local pos = amap[val]
  stcnt:addValue(pos, 1)
  stval:addValue(pos, val)
end
local function check()
  local lb = stcnt:lower_bound(hk)
  local left_cnt = lb == 1 and 0 or stcnt:getRange(1, lb - 1)
  local left_sum = lb == 1 and 0 or stval:getRange(1, lb - 1)
  local right_cnt = stcnt:getRange(lb, an)
  local right_sum = stval:getRange(lb, an)
  return right_sum - right_cnt * auniq[lb] + left_cnt * auniq[lb] - left_sum
end
local ret = check()
for i = k + 1, n do
  local val = a[i]
  local pos = amap[val]
  stcnt:addValue(pos, 1)
  stval:addValue(pos, val)
  val = a[i - k]
  pos = amap[val]
  stcnt:addValue(pos, -1)
  stval:addValue(pos, -val)
  ret = mmi(ret, check())
end
print(ret)
0