#ifdef NACHIA #define _GLIBCXX_DEBUG #else #define NDEBUG #endif #include #include #include #include #include #include #include #include #include using namespace std; using i64 = long long; using u64 = unsigned long long; #define rep(i,n) for(i64 i=0; i<(i64)(n); i++) #define repr(i,n) for(i64 i=(i64)(n)-1; i>=0; i--) const i64 INF = 1001001001001001001; const char* yn(bool x){ return x ? "Yes" : "No"; } template void chmin(A& l, const A& r){ if(r < l) l = r; } template void chmax(A& l, const A& r){ if(l < r) l = r; } template using nega_queue = priority_queue,greater>; using Modint = atcoder::static_modint<998244353>; #include #include template struct vec; template struct seq_view{ using Ref = typename std::iterator_traits::reference; using Elem = typename std::iterator_traits::value_type; Iter a, b; Iter begin() const { return a; } Iter end() const { return b; } int size() const { return (int)(b-a); } seq_view(Iter first, Iter last) : a(first), b(last) {} seq_view sort() const { std::sort(a, b); return *this; } Ref& operator[](int x){ return *(a+x); } template, class ret = vec> ret sorti(F f = F()) const { ret x(size()); for(int i=0; i> ret col() const { return ret(begin(), end()); } template, class ret = vec>> ret rle(F eq = F()) const { auto x = ret(); for(auto& a : (*this)){ if(x.size() == 0 || !eq(x[x.size()-1].first, a)) x.emp(a, 1); else x[x.size()-1].second++; } return x; } template seq_view sort(F f) const { std::sort(a, b, f); return *this; } Iter uni() const { return std::unique(a, b); } Iter lb(const Elem& x) const { return std::lower_bound(a, b, x); } Iter ub(const Elem& x) const { return std::upper_bound(a, b, x); } int lbi(const Elem& x) const { return lb(x) - a; } int ubi(const Elem& x) const { return ub(x) - a; } seq_view bound(const Elem& l, const Elem& r) const { return { lb(l), lb(r) }; } template Iter lb(const Elem& x, F f) const { return std::lower_bound(a, b, x, f); } template Iter ub(const Elem& x, F f) const { return std::upper_bound(a, b, x, f); } template Iter when_true_to_false(F f) const { if(a == b) return a; return std::lower_bound(a, b, *a, [&](const Elem& x, const Elem&){ return f(x); }); } seq_view same(Elem x) const { return { lb(x), ub(x) }; } template auto map(F f) const { vec r; for(auto& x : *this) r.emp(f(x)); return r; } Iter max() const { return std::max_element(a, b); } Iter min() const { return std::min_element(a, b); } template> Iter min(F f) const { return std::min_element(a, b, f); } seq_view rev() const { std::reverse(a, b); return *this; } }; template struct vec { using Base = typename std::vector; using Iter = typename Base::iterator; using CIter = typename Base::const_iterator; using View = seq_view; using CView = seq_view; vec(){} explicit vec(int n, const Elem& value = Elem()) : a(0 vec(I2 first, I2 last) : a(first, last) {} vec(std::initializer_list il) : a(std::move(il)) {} vec(Base b) : a(std::move(b)) {} operator Base() const { return a; } Iter begin(){ return a.begin(); } CIter begin() const { return a.begin(); } Iter end(){ return a.end(); } CIter end() const { return a.end(); } int size() const { return a.size(); } bool empty() const { return a.empty(); } Elem& back(){ return a.back(); } const Elem& back() const { return a.back(); } vec sortunied(){ vec x = *this; x().sort(); x.a.erase(x().uni(), x.end()); return x; } Iter operator()(int x){ return a.begin() + x; } CIter operator()(int x) const { return a.begin() + x; } View operator()(int l, int r){ return { (*this)(l), (*this)(r) }; } CView operator()(int l, int r) const { return { (*this)(l), (*this)(r) }; } View operator()(){ return (*this)(0,size()); } CView operator()() const { return (*this)(0,size()); } Elem& operator[](int x){ return a[x]; } const Elem& operator[](int x) const { return a[x]; } Base& operator*(){ return a; } const Base& operator*() const { return a; } vec& push(Elem args){ a.push_back(std::move(args)); return *this; } template vec& emp(Args &&... args){ a.emplace_back(std::forward(args) ...); return *this; } template vec& app(Range& x){ for(auto& v : a) emp(v); } Elem pop(){ Elem x = std::move(a.back()); a.pop_back(); return x; } bool operator==(const vec& r) const { return a == r.a; } bool operator!=(const vec& r) const { return a != r.a; } bool operator<(const vec& r) const { return a < r.a; } bool operator<=(const vec& r) const { return a <= r.a; } bool operator>(const vec& r) const { return a > r.a; } bool operator>=(const vec& r) const { return a >= r.a; } vec> pile(int n) const { return vec>(n, *this); } template vec& filter(F f){ int p = 0; for(int q=0; q IStr& operator>>(IStr& is, vec>& v){ for(auto& x:v){ is >> x.first >> x.second; } return is; } template IStr& operator>>(IStr& is, vec& v){ for(auto& x:v){ is >> x; } return is; } template OStr& operator<<(OStr& os, const vec& v){ for(int i=0; i namespace nachia{ template struct PrimitiveRoot{ using u64 = unsigned long long; static constexpr u64 powm(u64 a, u64 i) { u64 res = 1, aa = a; while(i){ if(i & 1) res = res * aa % MOD; aa = aa * aa % MOD; i /= 2; } return res; } static constexpr bool ExamineVal(unsigned int g){ unsigned int t = MOD - 1; for(u64 d=2; d*d<=t; d++) if(t % d == 0){ if(powm(g, (MOD - 1) / d) == 1) return false; while(t % d == 0) t /= d; } if(t != 1) if(powm(g, (MOD - 1) / t) == 1) return false; return true; } static constexpr unsigned int GetVal(){ for(unsigned int x=2; x class Comb{ private: static constexpr int MOD = Modint::mod(); std::vector F; std::vector iF; public: void extend(int newN){ int prevN = (int)F.size() - 1; if(newN >= MOD) newN = MOD - 1; if(prevN >= newN) return; F.resize(newN+1); iF.resize(newN+1); for(int i=prevN+1; i<=newN; i++) F[i] = F[i-1] * Modint::raw(i); iF[newN] = F[newN].inv(); for(int i=newN; i>prevN; i--) iF[i-1] = iF[i] * Modint::raw(i); } Comb(int n = 1){ F.assign(2, Modint(1)); iF.assign(2, Modint(1)); extend(n); } Modint factorial(int n) const { return F[n]; } Modint invFactorial(int n) const { return iF[n]; } Modint invOf(int n) const { return iF[n] * F[n-1]; } Modint comb(int n, int r) const { if(n < 0 || n < r || r < 0) return Modint(0); return F[n] * iF[r] * iF[n-r]; } Modint invComb(int n, int r) const { if(n < 0 || n < r || r < 0) return Modint(0); return iF[n] * F[r] * F[n-r]; } Modint perm(int n, int r) const { if(n < 0 || n < r || r < 0) return Modint(0); return F[n] * iF[n-r]; } Modint invPerm(int n, int r) const { if(n < 0 || n < r || r < 0) return Modint(0); return iF[n] * F[n-r]; } Modint operator()(int n, int r) const { return comb(n,r); } }; } // namespace nachia namespace nachia{ int Popcount(unsigned long long c) noexcept { #ifdef __GNUC__ return __builtin_popcountll(c); #else c = (c & (~0ull/3)) + ((c >> 1) & (~0ull/3)); c = (c & (~0ull/5)) + ((c >> 2) & (~0ull/5)); c = (c & (~0ull/17)) + ((c >> 4) & (~0ull/17)); c = (c * (~0ull/257)) >> 56; return c; #endif } // please ensure x != 0 int MsbIndex(unsigned long long x) noexcept { #ifdef __GNUC__ return 63 - __builtin_clzll(x); #else using u64 = unsigned long long; int q = (n >> 32) ? 32 : 0; auto m = n >> q; constexpr u64 hi = 0x8888'8888; constexpr u64 mi = 0x1111'1111; m = (((m | ~(hi - (m & ~hi))) & hi) * mi) >> 35; m = (((m | ~(hi - (n & ~hi))) & hi) * mi) >> 31; q += (m & 0xf) << 2; q += 0x3333'3333'2222'1100 >> (((n >> q) & 0xf) << 2) & 0xf return q; #endif } // please ensure x != 0 int LsbIndex(unsigned long long x) noexcept { #ifdef __GNUC__ return __builtin_ctzll(x); #else return MsbIndex(x & -x); #endif } } namespace nachia { template struct NttInterface{ template void Butterfly(Iter, int) const {} template void IButterfly(Iter, int) const {} template void BitReversal(Iter a, int N) const { for(int i=0, j=0; j>1; k > (i^=k); k>>=1); } } }; } // namespace nachia namespace nachia{ constexpr int bsf_constexpr(unsigned int n) { int x = 0; while (!(n & (1 << x))) x++; return x; } template struct NttFromAcl : NttInterface { using u32 = unsigned int; using u64 = unsigned long long; static int ceil_pow2(int n) { int x = 0; while ((1U << x) < (u32)(n)) x++; return x; } struct fft_info { static constexpr u32 g = nachia::PrimitiveRoot::val; static constexpr int rank2 = bsf_constexpr(mint::mod()-1); std::array root; std::array iroot; std::array rate2; std::array irate2; std::array rate3; std::array irate3; fft_info(){ root[rank2] = mint(g).pow((mint::mod() - 1) >> rank2); iroot[rank2] = root[rank2].inv(); for(int i=rank2-1; i>=0; i--){ root[i] = root[i+1] * root[i+1]; iroot[i] = iroot[i+1] * iroot[i+1]; } mint prod = 1, iprod = 1; for(int i=0; i<=rank2-2; i++){ rate2[i] = root[i+2] * prod; irate2[i] = iroot[i+2] * iprod; prod *= iroot[i+2]; iprod *= root[i+2]; } prod = 1; iprod = 1; for(int i=0; i<=rank2-3; i++){ rate3[i] = root[i+3] * prod; irate3[i] = iroot[i+3] * iprod; prod *= iroot[i+3]; iprod *= root[i+3]; } } }; template void Butterfly(RandomAccessIterator a, int n) const { int h = ceil_pow2(n); static const fft_info info; int len = 0; while(len < h){ if(h-len == 1){ int p = 1 << (h-len-1); mint rot = 1; for(int s=0; s<(1< void IButterfly(RandomAccessIterator a, int n) const { int h = ceil_pow2(n); static const fft_info info; constexpr int MOD = mint::mod(); int len = h; while(len){ if(len == 1){ int p = 1 << (h-len); mint irot = 1; for(int s=0; s<(1<<(len-1)); s++){ int offset = s << (h-len+1); for(int i=0; i> struct FpsNtt { public: using Fps = FpsNtt; using ElemTy = Elem; static constexpr unsigned int MOD = Elem::mod(); static constexpr int CONV_THRES = 30; static const NttInst nttInst; static const unsigned int zeta = nachia::PrimitiveRoot::GetVal(); private: using u32 = unsigned int; static Elem ZeroElem() noexcept { return Elem(0); } static Elem OneElem() noexcept { return Elem(1); } static Comb comb; std::vector a; int RSZ(int& sz) const { return sz = (sz < 0 ? size() : sz); } public: int size() const noexcept { return a.size(); } Elem& operator[](int x) noexcept { return a[x]; } const Elem& operator[](int x) const noexcept { return a[x]; } Elem getCoeff(int x) const noexcept { return (0 <= x && x < size()) ? a[x] : ZeroElem(); } static Comb& GetComb() { return comb; } static int BestNttSize(int x) noexcept { assert(x); return 1 << MsbIndex(x*2-1); } Fps move(){ return std::move(*this); } Fps& set(int i, Elem c){ a[i] = c; return *this; } Fps& removeLeadingZeros(){ int newsz = size(); while(newsz && a[newsz-1].val() == 0) newsz--; a.resize(newsz); if((int)a.capacity() / 4 > newsz) a.shrink_to_fit(); return *this; } FpsNtt(){} FpsNtt(int sz) : a(sz, ZeroElem()) {} FpsNtt(int sz, Elem e) : a(sz, e) {} FpsNtt(std::vector&& src) : a(std::move(src)) {} FpsNtt(const std::vector& src) : a(src) {} Fps& ntt() { capSize(BestNttSize(size())); nttInst.Butterfly(a.begin(), size()); return *this; } Fps& intt() { nttInst.IButterfly(a.begin(), a.size()); return times(Elem::raw(size()).inv()); } Fps nttDouble(Fps vanilla) const { int n = size(); assert(n == (n&-n)); // n is a power of 2 Elem q = Elem::raw(zeta).pow((Elem::mod() - 1) / (n*2)); Elem qq = OneElem(); for(int i=0; i srcR = max(srcL, size()); // if resSz is unspecified -> resSz = destL + srcR - srcL Fps clip(int srcL, int srcR = -1, int destL = 0, int resSz = -1) const { srcR = RSZ(srcR); if(resSz < 0) resSz = destL + srcR - srcL; int rj = std::min(std::min(srcR, size()) - srcL, resSz - destL); Fps res(resSz); for(int j=std::max(0, -srcL); j b.size()) return convolution(b, a, sz); if(sz < 0) sz = std::max(0, a.size() + b.size() - 1); std::vector res(sz); for(int i=0; i=1; i--) a[i] = a[i-1] * comb.invOf(i); return set(0, ZeroElem()); } Fps& EgfToOgf(){ comb.extend(size()); for(int i=0; i= (n-1) / k + 1) return Fps(n); Elem a0 = a[ctz]; return clip(ctz, ctz+n-ctz*k).times(a0.inv()).log().times(Elem(k)).exp().times(a0.pow(k)).clip(0, -1, ctz*k); } auto begin(){ return a.begin(); } auto end(){ return a.end(); } auto begin() const { return a.begin(); } auto end() const { return a.end(); } std::string toString(std::string beg = "[ ", std::string delim = " ", std::string en = " ]") const { std::string res = beg; bool f = false; for(auto x : a){ if(f){ res += delim; } f = true; res += std::to_string(x.val()); } res += en; return res; } std::vector getVectorMoved(){ return std::move(a); } Fps& operator+=(const Fps& r){ capSize(std::max(size(), r.size())); for(int i=0; i=0; i--) res = res * x + a[i]; return res; } }; template Comb FpsNtt::comb; template const NttInst FpsNtt::nttInst; } // namespace nachia namespace nachia{ template class CsrArray{ public: struct ListRange{ using iterator = typename std::vector::iterator; iterator begi, endi; iterator begin() const { return begi; } iterator end() const { return endi; } int size() const { return (int)std::distance(begi, endi); } Elem& operator[](int i) const { return begi[i]; } }; struct ConstListRange{ using iterator = typename std::vector::const_iterator; iterator begi, endi; iterator begin() const { return begi; } iterator end() const { return endi; } int size() const { return (int)std::distance(begi, endi); } const Elem& operator[](int i) const { return begi[i]; } }; private: int m_n; std::vector m_list; std::vector m_pos; public: CsrArray() : m_n(0), m_list(), m_pos() {} static CsrArray Construct(int n, std::vector> items){ CsrArray res; res.m_n = n; std::vector buf(n+1, 0); for(auto& [u,v] : items){ ++buf[u]; } for(int i=1; i<=n; i++) buf[i] += buf[i-1]; res.m_list.resize(buf[n]); for(int i=(int)items.size()-1; i>=0; i--){ res.m_list[--buf[items[i].first]] = std::move(items[i].second); } res.m_pos = std::move(buf); return res; } static CsrArray FromRaw(std::vector list, std::vector pos){ CsrArray res; res.m_n = pos.size() - 1; res.m_list = std::move(list); res.m_pos = std::move(pos); return res; } ListRange operator[](int u) { return ListRange{ m_list.begin() + m_pos[u], m_list.begin() + m_pos[u+1] }; } ConstListRange operator[](int u) const { return ConstListRange{ m_list.begin() + m_pos[u], m_list.begin() + m_pos[u+1] }; } int size() const { return m_n; } int fullSize() const { return (int)m_list.size(); } }; } // namespace nachia namespace nachia{ struct Graph { public: struct Edge{ int from, to; void reverse(){ std::swap(from, to); } }; using Base = std::vector>; Graph(int n = 0, bool undirected = false, int m = 0) : m_n(n), m_e(m), m_isUndir(undirected) {} Graph(int n, const std::vector>& edges, bool undirected = false) : m_n(n), m_isUndir(undirected){ m_e.resize(edges.size()); for(std::size_t i=0; i static Graph Input(Cin& cin, int n, bool undirected, int m, bool offset = 0){ Graph res(n, undirected, m); for(int i=0; i> u >> v; res[i].from = u - offset; res[i].to = v - offset; } return res; } int numVertices() const noexcept { return m_n; } int numEdges() const noexcept { return int(m_e.size()); } int addNode() noexcept { return m_n++; } int addEdge(int from, int to){ m_e.push_back({ from, to }); return numEdges() - 1; } Edge& operator[](int ei) noexcept { return m_e[ei]; } const Edge& operator[](int ei) const noexcept { return m_e[ei]; } Edge& at(int ei) { return m_e.at(ei); } const Edge& at(int ei) const { return m_e.at(ei); } auto begin(){ return m_e.begin(); } auto end(){ return m_e.end(); } auto begin() const { return m_e.begin(); } auto end() const { return m_e.end(); } bool isUndirected() const noexcept { return m_isUndir; } void reverseEdges() noexcept { for(auto& e : m_e) e.reverse(); } void contract(int newV, const std::vector& mapping){ assert(numVertices() == int(mapping.size())); for(int i=0; i induce(int num, const std::vector& mapping) const { int n = numVertices(); assert(n == int(mapping.size())); for(int i=0; i indexV(n), newV(num); for(int i=0; i= 0) indexV[i] = newV[mapping[i]]++; std::vector res; res.reserve(num); for(int i=0; i= 0) res[mapping[e.to]].addEdge(indexV[e.from], indexV[e.to]); return res; } CsrArray getEdgeIndexArray(bool undirected) const { std::vector> src; src.reserve(numEdges() * (undirected ? 2 : 1)); for(int i=0; i::Construct(numVertices(), src); } CsrArray getEdgeIndexArray() const { return getEdgeIndexArray(isUndirected()); } CsrArray getAdjacencyArray(bool undirected) const { std::vector> src; src.reserve(numEdges() * (undirected ? 2 : 1)); for(auto e : m_e){ src.emplace_back(e.from, e.to); if(undirected) src.emplace_back(e.to, e.from); } return CsrArray::Construct(numVertices(), src); } CsrArray getAdjacencyArray() const { return getAdjacencyArray(isUndirected()); } private: int m_n; std::vector m_e; bool m_isUndir; }; } // namespace nachia #include using Fps = nachia::FpsNtt; template Modint KthTermOfRationalGF( std::vector denom, std::vector numer, unsigned long long K ){ assert(denom.size() != 0); assert(denom.size() == numer.size()); assert(denom[0].val() != 0); int n = (int)denom.size(); while(K != 0){ auto Qn = denom; Qn.push_back(Modint(0)); for(int i=1; i> N >> M >> S >> T; S--; T--; int Tp = T; if(S == Tp) Tp = 0; if(S == Tp) Tp = 1; auto tree = nachia::Graph::Input(cin, N, true, N-1, 1); auto adj = tree.getAdjacencyArray(); vector parent(N, -1); vector bfs = { S }; vector dsize(N, 1); rep(i,N){ int v = bfs[i]; for(int w : adj[v]) if(parent[v] != w){ bfs.push_back(w); parent[w] = v; } } repr(i,N){ int v = bfs[i]; if(i != 0) dsize[parent[v]] += dsize[v]; } FracX fBase; fBase.p1 = Fps(3).set(2,1).move(); fBase.q1 = Fps(1).set(0,1).move(); fBase.qx = Fps(1).set(0,-1).move(); for(auto& e : tree) if(parent[e.to] != e.from) e.reverse(); adj = tree.getAdjacencyArray(false); auto findFrac = [&](auto& findFrac, int v) -> Frac { vector buf; buf.push_back(fBase); int p = v; while(true){ if(adj[p].size() == 0) break; for(int e=1; e cs; for(int e=1; e dp(N); dp[S] = 1; Fps dpres(101); dpres[0] = 1; rep(t,100){ vec tmp(N); for(auto [u,v] : tree){ tmp[u] += dp[v]; tmp[v] += dp[u]; } swap(dp, tmp); dpres[t+1] = dp[S]; } Fps sres(101); rep(t,101) sres[t] = KthTermOfRationalGF(ansf.q.clip(0,sz).getVectorMoved(), ansf.p.clip(0,sz).getVectorMoved(), t); cout << dpres.toString() << endl; cout << sres.toString() << endl; } int main(){ ios::sync_with_stdio(false); cin.tie(nullptr); #ifdef NACHIA int T; cin >> T; for(int t=0; t