結果
問題 | No.3046 yukicoderの過去問 |
ユーザー | chaemon |
提出日時 | 2020-07-19 16:17:33 |
言語 | Nim (2.0.2) |
結果 |
RE
(最新)
AC
(最初)
|
実行時間 | - |
コード長 | 24,575 bytes |
コンパイル時間 | 6,140 ms |
コンパイル使用メモリ | 79,616 KB |
実行使用メモリ | 5,376 KB |
最終ジャッジ日時 | 2024-05-09 15:41:06 |
合計ジャッジ時間 | 8,664 ms |
ジャッジサーバーID (参考情報) |
judge1 / judge2 |
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テストケース
テストケース表示入力 | 結果 | 実行時間 実行使用メモリ |
---|---|---|
testcase_00 | RE | - |
testcase_01 | RE | - |
testcase_02 | RE | - |
testcase_03 | RE | - |
testcase_04 | RE | - |
testcase_05 | RE | - |
testcase_06 | RE | - |
testcase_07 | RE | - |
testcase_08 | RE | - |
ソースコード
#{{{ header {.hints:off warnings:off optimization:speed.} import algorithm, sequtils, tables, macros, math, sets, strutils, strformat, sugar when defined(MYDEBUG): import header import streams proc scanf(formatstr: cstring){.header: "<stdio.h>", varargs.} #proc getchar(): char {.header: "<stdio.h>", varargs.} proc nextInt(): int = scanf("%lld",addr result) proc nextFloat(): float = scanf("%lf",addr result) proc nextString[F](f:F): string = var get = false result = "" while true: # let c = getchar() let c = f.readChar if c.int > ' '.int: get = true result.add(c) elif get: return proc nextInt[F](f:F): int = parseInt(f.nextString) proc nextFloat[F](f:F): float = parseFloat(f.nextString) proc nextString():string = stdin.nextString() template `max=`*(x,y:typed):void = x = max(x,y) template `min=`*(x,y:typed):void = x = min(x,y) template inf(T): untyped = when T is SomeFloat: T(Inf) elif T is SomeInteger: ((T(1) shl T(sizeof(T)*8-2)) - (T(1) shl T(sizeof(T)*4-1))) else: assert(false) proc discardableId[T](x: T): T {.discardable.} = return x macro `:=`(x, y: untyped): untyped = var strBody = "" if x.kind == nnkPar: for i,xi in x: strBody &= fmt""" {xi.repr} := {y[i].repr} """ else: strBody &= fmt""" when declaredInScope({x.repr}): {x.repr} = {y.repr} else: var {x.repr} = {y.repr} """ strBody &= fmt"discardableId({x.repr})" parseStmt(strBody) proc toStr[T](v:T):string = proc `$`[T](v:seq[T]):string = v.mapIt($it).join(" ") return $v proc print0(x: varargs[string, toStr]; sep:string):string{.discardable.} = result = "" for i,v in x: if i != 0: addSep(result, sep = sep) add(result, v) result.add("\n") stdout.write result var print:proc(x: varargs[string, toStr]) print = proc(x: varargs[string, toStr]) = discard print0(@x, sep = " ") template makeSeq(x:int; init):auto = when init is typedesc: newSeq[init](x) else: newSeqWith(x, init) macro Seq(lens: varargs[int]; init):untyped = var a = fmt"{init.repr}" for i in countdown(lens.len - 1, 0): a = fmt"makeSeq({lens[i].repr}, {a})" parseStmt(a) template makeArray(x; init):auto = when init is typedesc: var v:array[x, init] else: var v:array[x, init.type] for a in v.mitems: a = init v macro Array(lens: varargs[typed], init):untyped = var a = fmt"{init.repr}" for i in countdown(lens.len - 1, 0): a = fmt"makeArray({lens[i].repr}, {a})" parseStmt(a) # }}} const Mod = 1000000007 # ModInt {{{ # ModInt[Mod] {{{ type ModInt[Mod: static[int]] = object v:int32 proc initModInt(a:SomeInteger, Mod:static[int]):ModInt[Mod] = var a = a.int a = a mod Mod if a < 0: a += Mod result.v = a.int32 proc getMod[Mod:static[int]](self: ModInt[Mod]):static int32 = self.Mod proc getMod[Mod:static[int]](self: typedesc[ModInt[Mod]]):static int32 = self.Mod macro declareModInt(Mod:static[int], t: untyped):untyped = var strBody = "" strBody &= fmt""" type {t.repr} = ModInt[{Mod.repr}] converter to{t.repr}(a:SomeInteger):{t.repr} = initModInt(a, {Mod.repr}) proc init{t.repr}(a:SomeInteger):{t.repr} = initModInt(a, {Mod.repr}) proc `$`(a:{t.repr}):string = $(a.v) """ parseStmt(strBody) when declared(Mod): declareModInt(Mod, Mint) ##}}} # DynamicModInt {{{ type DMint = object v:int32 proc setModSub(self:typedesc[not ModInt], m:int = -1, update = false):int32 = {.noSideEffect.}: var DMOD {.global.}:int32 if update: DMOD = m.int32 return DMOD proc fastMod(a:int,m:uint32):uint32{.inline.} = var minus = false a = a if a < 0: minus = true a = -a elif a < m.int: return a.uint32 var xh = (a shr 32).uint32 xl = a.uint32 d:uint32 asm """ "divl %4; \n\t" : "=a" (`d`), "=d" (`result`) : "d" (`xh`), "a" (`xl`), "r" (`m`) """ if minus and result > 0'u32: result = m - result proc initDMint(a:SomeInteger, Mod:int):DMint = result.v = fastMod(a.int, Mod.uint32).int32 proc getMod[T:not ModInt](self: T):int32 = T.type.setModSub() proc getMod(self: typedesc[not ModInt]):int32 = self.setModSub() proc setMod(self: typedesc[not ModInt], m:int) = discard self.setModSub(m, update = true) #}}} # Operations {{{ type ModIntC = concept x, type T x.v # x.v is int32 # x.getMod() is int32 # when T isnot ModInt: setMod(T, int) type SomeIntC = concept x x is SomeInteger or x is ModIntC proc Identity(self:ModIntC):auto = result = self;result.v = 1 proc init[Mod:static[int]](self:ModInt[Mod], a:SomeIntC):ModInt[Mod] = when a is SomeInteger: initModInt(a, Mod) else: a proc init(self:ModIntC and not ModInt, a:SomeIntC):auto = when a is SomeInteger: var r = self.type.default r.v = fastMod(a.int, self.getMod().uint32).int32 r else: a macro declareDMintConverter(t:untyped) = parseStmt(fmt""" converter to{t.repr}(a:SomeInteger):{t.repr} = let Mod = {t.repr}.getMod() if Mod > 0: result.v = fastMod(a.int, Mod.uint32).int32 else: result.v = a.int32 return result """) declareDMintConverter(DMint) macro declareDMint(t:untyped) = parseStmt(fmt""" type {t.repr} {{.borrow: `.`.}} = distinct DMint declareDMintConverter({t.repr}) """) proc `*=`(self:var ModIntC, a:SomeIntC) = when self is ModInt: self.v = (self.v.int * self.init(a).v.int mod self.getMod().int).int32 else: self.v = fastMod(self.v.int * self.init(a).v.int, self.getMod().uint32).int32 proc `==`(a:ModIntC, b:SomeIntC):bool = a.v == a.init(b).v proc `!=`(a:ModIntC, b:SomeIntC):bool = a.v != a.init(b).v proc `-`(self:ModIntC):auto = if self.v == 0: return self else: return self.init(self.getMod() - self.v) proc `$`(a:ModIntC):string = return $(a.v) proc `+=`(self:var ModIntC; a:SomeIntC) = self.v += self.init(a).v if self.v >= self.getMod(): self.v -= self.getMod() proc `-=`(self:var ModIntC, a:SomeIntC) = self.v -= self.init(a).v if self.v < 0: self.v += self.getMod() proc `^=`(self:var ModIntC, n:SomeInteger) = var (x,n,a) = (self,n,self.Identity) while n > 0: if (n and 1) > 0: a *= x x *= x n = (n shr 1) swap(self, a) proc inverse(self: ModIntC):auto = var a = self.v.int b = self.getMod().int u = 1 v = 0 while b > 0: let t = a div b a -= t * b;swap(a, b) u -= t * v;swap(u, v) return self.init(u) proc `/=`(a:var ModIntC,b:SomeIntC) = a *= a.init(b).inverse() proc `+`(a:ModIntC,b:SomeIntC):auto = result = a;result += b proc `-`(a:ModIntC,b:SomeIntC):auto = result = a;result -= b proc `*`(a:ModIntC,b:SomeIntC):auto = result = a;result *= b proc `/`(a:ModIntC,b:SomeIntC):auto = result = a;result /= b proc `^`(a:ModIntC,b:SomeInteger):auto = result = a;result ^= b # }}} # }}} #{{{ FastFourierTransform # clongdouble {{{ proc `+`(a, b:clongdouble):clongdouble {.importcpp: "(#) + (@)", nodecl.} proc `-`(a, b:clongdouble):clongdouble {.importcpp: "(#) - (@)", nodecl.} proc `*`(a, b:clongdouble):clongdouble {.importcpp: "(#) * (@)", nodecl.} proc `/`(a, b:clongdouble):clongdouble {.importcpp: "(#) / (@)", nodecl.} proc `-`(a:clongdouble):clongdouble {.importcpp: "-(#)", nodecl.} proc sqrt(a:clongdouble):clongdouble {.header: "<cmath>", importcpp: "sqrtl(#)", nodecl.} proc exp(a:clongdouble):clongdouble {.header: "<cmath>", importcpp: "expl(#)", nodecl.} proc sin(a:clongdouble):clongdouble {.header: "<cmath>", importcpp: "sinl(#)", nodecl.} proc acos(a:clongdouble):clongdouble {.header: "<cmath>", importcpp: "acosl(#)", nodecl.} proc cos(a:clongdouble):clongdouble {.header: "<cmath>", importcpp: "cosl(#)", nodecl.} proc llround(a:clongdouble):int {.header: "<cmath>", importcpp: "std::llround(#)", nodecl.} # }}} import math, sequtils, bitops #type Real = float type Real = clongdouble type C = tuple[x, y:Real] proc initC[S,T](x:S, y:T):C = (Real(x), Real(y)) proc `+`(a,b:C):C = initC(a.x + b.x, a.y + b.y) proc `-`(a,b:C):C = initC(a.x - b.x, a.y - b.y) proc `*`(a,b:C):C = initC(a.x * b.x - a.y * b.y, a.x * b.y + a.y * b.x) proc conj(a:C):C = initC(a.x, -a.y) type SeqC = object real, imag: seq[Real] proc initSeqC(n:int):SeqC = SeqC(real: newSeqWith(n, Real(0)), imag: newSeqWith(n, Real(0))) proc setLen(self: var SeqC, n:int) = self.real.setLen(n) self.imag.setLen(n) proc swap(self: var SeqC, i, j:int) = swap(self.real[i], self.real[j]) swap(self.imag[i], self.imag[j]) type FastFourierTransform = object of RootObj base:int rts: SeqC rev:seq[int] proc getC(self: SeqC, i:int):C = (self.real[i], self.imag[i]) proc `[]`(self: SeqC, i:int):C = self.getC(i) proc `[]=`(self: var SeqC, i:int, x:C) = self.real[i] = x.x self.imag[i] = x.y proc initFastFourierTransform():FastFourierTransform = return FastFourierTransform(base:1, rts: SeqC(real: @[Real(0), Real(1)], imag: @[Real(0), Real(0)]), rev: @[0, 1]) #proc init(self:typedesc[FastFourierTransform]):auto = initFastFourierTransform() proc ensureBase(self:var FastFourierTransform; nbase:int) = if nbase <= self.base: return let L = 1 shl nbase self.rev.setlen(1 shl nbase) self.rts.setlen(1 shl nbase) for i in 0..<(1 shl nbase): self.rev[i] = (self.rev[i shr 1] shr 1) + ((i and 1) shl (nbase - 1)) while self.base < nbase: let angle = acos(Real(-1)) * Real(2) / Real(1 shl (self.base + 1)) for i in (1 shl (self.base - 1))..<(1 shl self.base): self.rts[i shl 1] = self.rts[i] let angle_i = angle * Real(2 * i + 1 - (1 shl self.base)) self.rts[(i shl 1) + 1] = initC(cos(angle_i), sin(angle_i)) self.base.inc proc fft(self:var FastFourierTransform; a:var SeqC, n:int) = assert((n and (n - 1)) == 0) let zeros = countTrailingZeroBits(n) self.ensureBase(zeros) let shift = self.base - zeros for i in 0..<n: if i < (self.rev[i] shr shift): a.swap(i, self.rev[i] shr shift) var k = 1 while k < n: var i = 0 while i < n: for j in 0..<k: let z = a[i + j + k] * self.rts[j + k] a[i + j + k] = a[i + j] - z a[i + j] = a[i + j] + z i += 2 * k k = k shl 1 proc ifft(self: var FastFourierTransform; a: var SeqC, n:int) = for i in 0..<n: a[i] = a[i].conj() let rN = clongdouble(1) / clongdouble(n) self.fft(a, n) for i in 0..<n: let t = a[i] a[i] = (t.x * rN, t.y * rN) proc multiply(self:var FastFourierTransform; a,b:seq[int]):seq[int] = let need = a.len + b.len - 1 var nbase = 1 while (1 shl nbase) < need: nbase.inc self.ensureBase(nbase) let sz = 1 shl nbase var fa = initSeqC(sz) for i in 0..<sz: let x = if i < a.len: a[i] else: 0 let y = if i < b.len: b[i] else: 0 fa[i] = initC(x, y) self.fft(fa, sz) let r = initC(0, - Real(1) / (Real((sz shr 1) * 4))) s = initC(0, 1) t = initC(Real(1)/Real(2), 0) for i in 0..(sz shr 1): let j = (sz - i) and (sz - 1) let z = (fa[j] * fa[j] - (fa[i] * fa[i]).conj()) * r fa[j] = (fa[i] * fa[i] - (fa[j] * fa[j]).conj()) * r fa[i] = z for i in 0..<(sz shr 1): let A0 = (fa[i] + fa[i + (sz shr 1)]) * t let A1 = (fa[i] - fa[i + (sz shr 1)]) * t * self.rts[(sz shr 1) + i] fa[i] = A0 + A1 * s self.fft(fa, sz shr 1) var ret = newSeq[int](need) for i in 0..<need: ret[i] = llround(if (i and 1)>0: fa[i shr 1].y else: fa[i shr 1].x) return ret var fft_t = initFastFourierTransform() #}}} const ArbitraryMod = true #{{{ ArbitraryModConvolution type ArbitraryModConvolution[ModInt] = object proc init[ModInt](t:typedesc[ArbitraryModConvolution[ModInt]]):auto = ArbitraryModConvolution[ModInt]() proc ceil_log2(n:int):int = result = 0 while (1 shl result) < n: result.inc proc fft[ModInt](self: var ArbitraryModConvolution[ModInt], a:seq[ModInt]):SeqC = doAssert((a.len and (a.len - 1)) == 0) let l = ceil_log2(a.len) fft_t.ensureBase(l) result = initSeqC(a.len) for i in 0..<a.len: result[i] = initC(a[i].v and ((1 shl 15) - 1), a[i].v shr 15) fft_t.fft(result, a.len) proc dot[ModInt](self: ArbitraryModConvolution[ModInt], fa: SeqC, fb:SeqC):(SeqC, SeqC) = let sz = fa.real.len var (fa, fb) = (fa, fb) let ratio = Real(1) / (Real(sz) * Real(4)) let r2 = initC(0, -1) r3 = initC(ratio, 0) r4 = initC(0, -ratio) r5 = initC(0, 1) for i in 0..(sz shr 1): let j = (sz - i) and (sz - 1) a1 = (fa[i] + fa[j].conj()) a2 = (fa[i] - fa[j].conj()) * r2 b1 = (fb[i] + fb[j].conj()) * r3 b2 = (fb[i] - fb[j].conj()) * r4 if i != j: let c1 = (fa[j] + fa[i].conj()) c2 = (fa[j] - fa[i].conj()) * r2 d1 = (fb[j] + fb[i].conj()) * r3 d2 = (fb[j] - fb[i].conj()) * r4 fa[i] = c1 * d1 + c2 * d2 * r5 fb[i] = c1 * d2 + c2 * d1 fa[j] = a1 * b1 + a2 * b2 * r5 fb[j] = a1 * b2 + a2 * b1 return (fa, fb) proc ifft[ModInt](self: var ArbitraryModConvolution[ModInt], p:(SeqC, SeqC), need = -1):seq[ModInt] = var (fa, fb) = p let sz = fa.real.len fft_t.fft(fa, sz) fft_t.fft(fb, sz) let need = if need == -1: fa.real.len else: need result = newSeq[ModInt](need) for i in 0..<need: var aa = llround(fa[i].x) bb = llround(fb[i].x) cc = llround(fa[i].y) aa = ModInt(aa).v; bb = ModInt(bb).v; cc = ModInt(cc).v result[i] = ModInt(aa + (bb shl 15) + (cc shl 30)) proc multiply[ModInt](self:var ArbitraryModConvolution[ModInt], a,b:seq[ModInt], need = -1):seq[ModInt] = var need = need if need == -1: need = a.len + b.len - 1 var nbase = ceil_log2(need) fft_t.ensureBase(nbase) let sz = 1 shl nbase var (a, b) = (a, b) a.setlen(sz) b.setlen(sz) var fa1 = self.fft(a) fb1 = if a == b: fa1 else: self.fft(b) (fa1, fb1) = self.dot(fa1, fb1) return self.ifft((fa1, fb1), need) #}}} const FastMod = true const UseFFT = true # FormalPowerSeries {{{ import sugar, sequtils, strformat, options type FieldElem = concept x, type T x + x x - x x * x x / x type FormalPowerSeries[T:FieldElem] = seq[T] when not declared(FastMult): const FastMult = true when not declared(UseFFT): const UseFFT = true when not declared(ArbitraryMod): const ArbitraryMod = false when UseFFT or FastMult: when ArbitraryMod: when declared(ArbitraryModConvolutionNTT): type BaseFFT[T] = ArbitraryModConvolutionNTT[T] elif declared(ArbitraryModConvolution): type BaseFFT[T] = ArbitraryModConvolution[T] else: assert(false) else: when declared(NumberTheoreticTransform): type BaseFFT[T] = NumberTheoreticTransform[T] else: assert(false) proc getFFT[T](self:FormalPowerSeries[T]):ptr BaseFFT[T] = var fft {.global.} = BaseFFT[T].init() return fft.addr proc initFormalPowerSeries[T:FieldElem](n:int):auto = FormalPowerSeries[T](newSeq[T](n)) template initFormalPowerSeries[T](data: openArray[typed]):FormalPowerSeries[T] = data.mapIt(T(it)) proc `$`[T](self:FormalPowerSeries[T]):string = return self.mapIt($it).join(" ") macro revise(a, b) = parseStmt(fmt"""let {a.repr} = if {a.repr} == -1: {b.repr} else: {a.repr}""") #{{{ sqrt type SQRT[T] = proc(t:T):Option[T] proc sqrtSub[T](self:FormalPowerSeries[T], update: bool, f:SQRT[T]):(bool, SQRT[T]){.discardable.} = var is_set{.global.} = false var sqr{.global.}:SQRT[T] = nil if update: is_set = true sqr = f return (is_set, sqr) proc isSetSqrt[T](self:FormalPowerSeries[T]):bool = return self.sqrtSub(false, nil)[0] proc setSqrt[T](self:FormalPowerSeries[T], f: SQRT[T]):SQRT[T]{.discardable.} = return self.sqrtSub(true, f)[1] proc getSqrt[T](self:FormalPowerSeries[T]):SQRT[T]{.discardable.} = return self.sqrtSub(false, nil)[1] #}}} proc shrink[T](self: var FormalPowerSeries[T]) = while self.len > 0 and self[^1] == 0: discard self.pop() #{{{ operators +=, -=, *=, mod=, -, /= proc `+=`(self: var FormalPowerSeries, r:FormalPowerSeries) = if r.len > self.len: self.setlen(r.len) for i in 0..<r.len: self[i] += r[i] proc `+=`[T](self: var FormalPowerSeries[T], r:T) = if self.len == 0: self.setlen(1) self[0] += r proc `-=`[T](self: var FormalPowerSeries[T], r:FormalPowerSeries[T]) = if r.len > self.len: self.setlen(r.len) for i in 0..<r.len: self[i] -= r[i] self.shrink() proc `-=`[T](self: var FormalPowerSeries[T], r:T) = if self.len == 0: self.setlen(1) self[0] -= r self.shrink() proc `*=`[T](self: var FormalPowerSeries[T], v:T) = self.applyIt(it * v) proc `*=`[T](self: var FormalPowerSeries[T], r: FormalPowerSeries[T]) = if self.len == 0 or r.len == 0: self.setlen(0) else: when FastMult: var fft = self.getFFT() self = fft[].multiply(self, r) else: var c = initFormalPowerSeries[T](self.len + r.len - 1) for i in 0..<self.len: for j in 0..<r.len: c[i + j] += self[i] + r[j] self.swap(c) proc `mod=`[T](self: var FormalPowerSeries[T], r:FormalPowerSeries[T]) = self -= self div r * r proc `-`[T](self: FormalPowerSeries[T]):FormalPowerSeries[T] = var ret = self ret.applyIt(-it) return ret proc `/=`[T](self: var FormalPowerSeries[T], v:T) = self.applyIt(it / v) #}}} proc rev[T](self: FormalPowerSeries[T], deg = -1):auto = var ret = self if deg != -1: ret.setlen(deg) ret.reverse return ret proc pre[T](self: FormalPowerSeries[T], sz:int):auto = result = self result.setlen(min(self.len, sz)) proc `div=`[T](self: var FormalPowerSeries[T], r: FormalPowerSeries[T]) = if self.len < r.len: self.setlen(0) else: let n = self.len - r.len + 1 self = (self.rev().pre(n) * r.rev().inv(n)).pre(n).rev(n) proc dot[T](self:FormalPowerSeries[T], r: FormalPowerSeries[T]):auto = var ret = initFormalPowerSeries[T](min(self.len, r.len)) for i in 0..<ret.len: ret[i] = self[i] * r[i] return ret proc `shr`[T](self: FormalPowerSeries[T], sz:int):auto = if self.len <= sz: return initFormalPowerSeries[T](0) result = self if sz >= 1: result.delete(0, sz - 1) proc `shl`[T](self: FormalPowerSeries[T], sz:int):auto = result = initFormalPowerSeries[T](sz) result = result & self proc diff[T](self: FormalPowerSeries[T]):auto = let n = self.len result = initFormalPowerSeries[T](max(0, n - 1)) for i in 1..<n: result[i - 1] = self[i] * T(i) proc integral[T](self: FormalPowerSeries[T]):auto = let n = self.len result = initFormalPowerSeries[T](n + 1) result[0] = T(0) for i in 0..<n: result[i + 1] = self[i] / T(i + 1) # F(0) must not be 0 proc inv[T](self: FormalPowerSeries[T], deg = -1):auto = doAssert(self[0] != 0) deg.revise(self.len) when UseFFT: proc invFast[T](self: FormalPowerSeries[T]):auto = doAssert(self[0] != 0) let n = self.len var res = initFormalPowerSeries[T](1) res[0] = T(1) / self[0] var fft = self.getFFT() var d = 1 while d < n: var f, g = initFormalPowerSeries[T](2 * d) for j in 0..<min(n, 2 * d): f[j] = self[j] for j in 0..<d: g[j] = res[j] let g1 = fft[].fft(g) f = fft[].ifft(fft[].dot(fft[].fft(f), g1)) for j in 0..<d: f[j] = T(0) f[j + d] = -f[j + d] f = fft[].ifft(fft[].dot(fft[].fft(f), g1)) f[0..<d] = res[0..<d] res = f d = d shl 1 return res.pre(n) var ret = self ret.setlen(deg) return ret.invFast() else: var ret = initFormalPowerSeries[T](1) ret[0] = T(1) / self[0] var i = 1 while i < deg: ret = (ret + ret - ret * ret * self.pre(i shl 1)).pre(i shl 1) i = i shl 1 return ret.pre(deg) # F(0) must be 1 proc log[T](self:FormalPowerSeries[T], deg = -1):auto = doAssert self[0] == T(1) deg.revise(self.len) return (self.diff() * self.inv(deg)).pre(deg - 1).integral() proc sqrt[T](self: FormalPowerSeries[T], deg = -1):auto = let n = self.len deg.revise(n) if self[0] == 0: for i in 1..<n: if self[i] != 0: if (i and 1) > 0: return FormalPowerSeries[T].none if deg - i div 2 <= 0: break var opt = (self shr i).sqrt(deg - i div 2) if not opt.isSome: return FormalPowerSeries[T].none var ret = opt.get shl (i div 2) if ret.len < deg: ret.setlen(deg) return ret.some return initFormalPowerSeries[T](deg).some var ret:FormalPowerSeries[T] if self.isSetSqrt: let opt = self.getSqrt()(self[0]) if not opt.isSome: return FormalPowerSeries[T].none ret = initFormalPowerSeries[T](@[T(opt.get)]) else: doAssert(self[0] == 1) ret = initFormalPowerSeries[T](@[T(1)]) let inv2 = T(1) / T(2); var i = 1 while i < deg: ret = (ret + self.pre(i shl 1) * ret.inv(i shl 1)) * inv2 i = i shl 1 return ret.pre(deg).some import typetraits # F(0) must be 0 proc exp[T](self: FormalPowerSeries[T], deg = -1):auto = doAssert self[0] == 0 deg.revise(self.len) when UseFFT: proc onlineConvolutionExp[T](self, conv_coeff:FormalPowerSeries[T]):auto = var fft = self.getFFT() let n = conv_coeff.len doAssert((n and (n - 1)) == 0) type FFTType = fft[].fft(initFormalPowerSeries[T](0)).type var conv_ntt_coeff = newSeq[FFTType]() i = n while (i shr 1) > 0: var g = conv_coeff.pre(i) conv_ntt_coeff.add(fft[].fft(g)) i = i shr 1 var conv_arg, conv_ret = initFormalPowerSeries[T](n) proc rec(l,r,d:int) = if r - l <= 16: for i in l..<r: var sum = T(0) for j in l..<i: sum += conv_arg[j] * conv_coeff[i - j] conv_ret[i] += sum conv_arg[i] = if i == 0: T(1) else: conv_ret[i] / i else: var m = (l + r) div 2 rec(l, m, d + 1) var pre = initFormalPowerSeries[T](r - l) pre[0..<m-l] = conv_arg[l..<m] pre = fft[].ifft(fft[].dot(fft[].fft(pre), conv_ntt_coeff[d])) for i in 0..<r - m: conv_ret[m + i] += pre[m + i - l] rec(m, r, d + 1) rec(0, n, 0) return conv_arg proc expRec[T](self: FormalPowerSeries[T]):auto = doAssert self[0] == 0 let n = self.len var m = 1 while m < n: m *= 2 var conv_coeff = initFormalPowerSeries[T](m) for i in 1..<n: conv_coeff[i] = self[i] * i return self.onlineConvolutionExp(conv_coeff).pre(n) var ret = self ret.setlen(deg) return ret.expRec() else: var ret = initFormalPowerSeries[T](@[T(1)]) i = 1 while i < deg: ret = (ret * (self.pre(i shl 1) + T(1) - ret.log(i shl 1))).pre(i shl 1); i = i shl 1 return ret.pre(deg) proc exponent[T](a:FormalPowerSeries[T]):FormalPowerSeries[T] = assert(a.len == 0 or a[0] == 0); var a = a b = initFormalPowerSeries[T]([1]) while b.len < a.len: var x = a[0..<min(a.len, 2 * b.len)] x[0] += 1 b.setLen(2 * b.len) x -= log(b) let l = b.len div 2 x *= b[0..<l] for i in l..<min(x.len, b.len): b[i] = x[i] return b[0..<a.len] proc pow[T](self: FormalPowerSeries[T], k:int, deg = -1):auto = var self = self let n = self.len deg.revise(n) self.setLen(deg) for i in 0..<n: if self[i] != T(0): let rev = T(1) / self[i] result = (((self * rev) shr i).log(deg) * T(k)).exp() * (self[i]^k) if i * k > deg: return initFormalPowerSeries[T](deg) result = (result shl (i * k)).pre(deg) if result.len < deg: result.setlen(deg) return return self proc eval[T](self: FormalPowerSeries[T], x:T):T = var r = T(0) w = T(1) for v in self: r += w * v w *= x return r proc powMod[T](self: FormalPowerSeries[T], n:int, M:FormalPowerSeries[T]):auto = let modinv = M.rev().inv() proc getDiv(base:FormalPowerSeries[T]):FormalPowerSeries[T] = var base = base if base.len < M.len: base.setlen(0) return base let n = base.len - M.len + 1 return (base.rev().pre(n) * modinv.pre(n)).pre(n).rev(n) var n = n x = self ret = initFormalPowerSeries[T](@[T(1)]) while n > 0: if (n and 1) > 0: ret *= x ret -= getDiv(ret) * M x *= x x -= getDiv(x) * M n = n shr 1 return ret # operators +, -, *, div, mod {{{ macro declareOp(op) = fmt"""proc `{op}`[T](self:FormalPowerSeries[T];r:FormalPowerSeries[T] or T):FormalPowerSeries[T] = result = self;result {op}= r""".parseStmt declareOp(`+`) declareOp(`-`) declareOp(`*`) declareOp(`/`) proc `div`[T](self, r:FormalPowerSeries[T]):FormalPowerSeries[T] = result = self;result.`div=` (r) proc `mod`[T](self, r:FormalPowerSeries[T]):FormalPowerSeries[T] = result = self;result.`mod=` (r) # }}} # }}} let K, N = nextInt() let x = Seq(N, nextInt()) let m = x.max var f = initFormalPowerSeries[Mint](100010) for x in x: f[x] = 1 f = -f f[0] += 1 echo(f.inv()[K])