#line 1 "other_algorithms/test/permutation_tree.yuki1720.test.cpp" #define PROBLEM "https://yukicoder.me/problems/no/1720" #line 2 "segmenttree/range-add-range-min.hpp" #include #include #include // CUT begin // StarrySkyTree: segment tree for Range Minimum Query & Range Add Query // Complexity: $O(N)$ (construction), $O(\log N)$ (add / get / prod) // - RangeAddRangeMin(std::vector data_init) : Initialize array x by data_init. // - add(int begin, int end, Tp vadd) : Update x[i] <- x[i] + vadd for all begin <= i < end. // - get(int pos) : Get x[pos]. // - prod(int begin, int end) : Get min(x[begin], ..., x[end - 1]). template ::max() / 2> struct RangeAddRangeMin { int N, head; std::vector range_min, range_add; static inline Tp f(Tp x, Tp y) noexcept { return std::min(x, y); } inline void _merge(int pos) { range_min[pos] = f(range_min[pos * 2] + range_add[pos * 2], range_min[pos * 2 + 1] + range_add[pos * 2 + 1]); } void initialize(const std::vector &data_init) { N = data_init.size(), head = 1; while (head < N) head <<= 1; range_min.assign(head * 2, defaultT); range_add.assign(head * 2, 0); std::copy(data_init.begin(), data_init.end(), range_min.begin() + head); for (int pos = head; --pos;) _merge(pos); } RangeAddRangeMin() = default; RangeAddRangeMin(const std::vector &data_init) { initialize(data_init); } void _add(int begin, int end, int pos, int l, int r, Tp vadd) noexcept { if (r <= begin or end <= l) return; if (begin <= l and r <= end) { range_add[pos] += vadd; return; } _add(begin, end, pos * 2, l, (l + r) / 2, vadd); _add(begin, end, pos * 2 + 1, (l + r) / 2, r, vadd); _merge(pos); } // Add `vadd` to (x_begin, ..., x_{end - 1}) void add(int begin, int end, Tp vadd) noexcept { return _add(begin, end, 1, 0, head, vadd); } Tp _get(int begin, int end, int pos, int l, int r) const noexcept { if (r <= begin or end <= l) return defaultT; if (begin <= l and r <= end) return range_min[pos] + range_add[pos]; return f(_get(begin, end, pos * 2, l, (l + r) / 2), _get(begin, end, pos * 2 + 1, (l + r) / 2, r)) + range_add[pos]; } // Return f(x_begin, ..., x_{end - 1}) Tp get(int pos) const noexcept { return prod(pos, pos + 1); } Tp prod(int begin, int end) const noexcept { return _get(begin, end, 1, 0, head); } }; #line 4 "other_algorithms/permutation_tree.hpp" #include #include #include #line 8 "other_algorithms/permutation_tree.hpp" // Permutation tree // Complexity: O(N log N) // https://codeforces.com/blog/entry/78898 https://yukicoder.me/problems/no/1720 struct permutation_tree { enum NodeType { JoinAsc, JoinDesc, Cut, Leaf, None, }; struct node { NodeType tp; int L, R; // i in [L, R) int mini, maxi; // A[i] in [mini, maxi] std::vector child; int sz() const { return R - L; } template friend OStream &operator<<(OStream &os, const node &n) { os << "[[" << n.L << ',' << n.R << ")(ch:"; for (auto i : n.child) os << i << ','; return os << ")(tp=" << n.tp << ")]"; } }; int root; std::vector A; std::vector nodes; void _add_child(int parid, int chid) { nodes[parid].child.push_back(chid); nodes[parid].L = std::min(nodes[parid].L, nodes[chid].L); nodes[parid].R = std::max(nodes[parid].R, nodes[chid].R); nodes[parid].mini = std::min(nodes[parid].mini, nodes[chid].mini); nodes[parid].maxi = std::max(nodes[parid].maxi, nodes[chid].maxi); } permutation_tree() : root(-1) {} permutation_tree(const std::vector &A_) : root(-1), A(A_) { // A: nonempty perm., 0-origin assert(!A.empty()); RangeAddRangeMin seg((std::vector(A.size()))); std::vector hi{-1}, lo{-1}; std::vector st; for (int i = 0; i < int(A.size()); ++i) { while (hi.back() >= 0 and A[i] > A[hi.back()]) { seg.add(hi[hi.size() - 2] + 1, hi.back() + 1, A[i] - A[hi.back()]); hi.pop_back(); } hi.push_back(i); while (lo.back() >= 0 and A[i] < A[lo.back()]) { seg.add(lo[lo.size() - 2] + 1, lo.back() + 1, A[lo.back()] - A[i]); lo.pop_back(); } lo.push_back(i); int h = nodes.size(); nodes.push_back({NodeType::Leaf, i, i + 1, A[i], A[i], std::vector{}}); while (true) { NodeType join_tp = NodeType::None; if (!st.empty() and nodes[st.back()].maxi + 1 == nodes[h].mini) join_tp = JoinAsc; if (!st.empty() and nodes[h].maxi + 1 == nodes[st.back()].mini) join_tp = JoinDesc; if (!st.empty() and join_tp != NodeType::None) { const node &vtp = nodes[st.back()]; // Insert v as the child of the top node in the stack if (join_tp == vtp.tp) { // Append child to existing Join node _add_child(st.back(), h); h = st.back(); st.pop_back(); } else { // Make new join node (with exactly two children) int j = st.back(); nodes.push_back( {join_tp, nodes[j].L, nodes[j].R, nodes[j].mini, nodes[j].maxi, {j}}); st.pop_back(); _add_child(nodes.size() - 1, h); h = nodes.size() - 1; } } else if (seg.prod(0, i + 1 - nodes[h].sz()) == 0) { // Make Cut node int L = nodes[h].L, R = nodes[h].R, maxi = nodes[h].maxi, mini = nodes[h].mini; nodes.push_back({NodeType::Cut, L, R, mini, maxi, {h}}); h = nodes.size() - 1; do { _add_child(h, st.back()); st.pop_back(); } while (nodes[h].maxi - nodes[h].mini + 1 != nodes[h].sz()); std::reverse(nodes[h].child.begin(), nodes[h].child.end()); } else { break; } } st.push_back(h); seg.add(0, i + 1, -1); } assert(st.size() == 1); root = st[0]; } void to_DOT(std::string filename = "") const { if (filename.empty()) filename = "permutation_tree_" + std::to_string(A.size()) + ".DOT"; std::ofstream ss(filename); ss << "digraph{\n"; int nleaf = 0; for (int i = 0; i < int(nodes.size()); i++) { ss << i << "[\n"; std::string lbl; if (nodes[i].tp == NodeType::Leaf) { lbl = "A[" + std::to_string(nleaf) + "] = " + std::to_string(A[nleaf]), nleaf++; } else { lbl += std::string(nodes[i].tp == NodeType::Cut ? "Cut" : "Join") + "\\n"; lbl += "[" + std::to_string(nodes[i].L) + ", " + std::to_string(nodes[i].R) + ")"; } ss << "label = \"" << lbl << "\",\n"; ss << "]\n"; for (const auto &ch : nodes[i].child) ss << i << " -> " << ch << ";\n"; } ss << "{rank = same;"; for (int i = 0; i < int(nodes.size()); i++) { if (nodes[i].tp == NodeType::Leaf) ss << ' ' << i << ';'; } ss << "}\n"; ss << "}\n"; ss.close(); return; } }; #include #line 5 "other_algorithms/test/permutation_tree.yuki1720.test.cpp" #include using namespace std; using mint = atcoder::modint998244353; int N, K; permutation_tree tree; vector> dp; void rec(int now) { const auto &v = tree.nodes[now]; if (v.tp == permutation_tree::Cut or v.tp == permutation_tree::Leaf) { for (int k = 0; k < K; ++k) dp[k + 1][v.R] += dp[k][v.L]; } vector sum(K); for (auto ch : v.child) { rec(ch); if (v.tp == permutation_tree::JoinAsc or v.tp == permutation_tree::JoinDesc) { for (int k = 0; k < K; ++k) { dp[k + 1][tree.nodes[ch].R] += sum[k]; sum[k] += dp[k][tree.nodes[ch].L]; } } } }; int main() { cin.tie(nullptr), ios::sync_with_stdio(false); cin >> N >> K; vector P(N); for (auto &x : P) cin >> x; for (auto &x : P) x--; tree = permutation_tree(P); dp.assign(K + 1, vector(N + 1)); dp[0][0] = 1; rec(tree.root); for (int i = 1; i <= K; i++) cout << dp[i][N].val() << '\n'; }