#line 1 "main.cpp" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* template start */ using i64 = std::int_fast64_t; using u64 = std::uint_fast64_t; i64 operator"" _i64(unsigned long long num){ return i64(num); } u64 operator"" _u64(unsigned long long num){ return u64(num); } #define rep(i, a, b) for (i64 i = (a); (i) < (b); (i)++) #define all(i) i.begin(), i.end() #ifdef LOCAL #define debug(...) \ std::cerr << "LINE: " << __LINE__ << " [" << #__VA_ARGS__ << "]:", \ debug_out(__VA_ARGS__) #else #define debug(...) #endif void debug_out() { std::cerr << std::endl; } template void debug_out(Head h, Tail... t) { std::cerr << " " << h; if (sizeof...(t) > 0) std::cout << " :"; debug_out(t...); } template std::ostream& operator<<(std::ostream& os, std::pair pa) { return os << pa.first << " " << pa.second; } template std::ostream& operator<<(std::ostream& os, std::vector vec) { for (std::size_t i = 0; i < vec.size(); i++) os << vec[i] << (i + 1 == vec.size() ? "" : " "); return os; } template inline bool chmax(T1& a, T2 b) { return a < b && (a = b, true); } template inline bool chmin(T1& a, T2 b) { return a > b && (a = b, true); } template constexpr Num mypow(Num a, u64 b, Num id = 1) { if (b == 0) return id; Num x = id; while (b > 0) { if (b & 1) x *= a; a *= a; b >>= 1; } return x; } /* template end */ #line 2 "/home/imperi/cp-library/lib/utility/modint.hpp" /* author:noshi91 reference:https://noshi91.hatenablog.com/entry/2019/03/31/174006 https://github.com/noshi91/Library/blob/master/other/modint.cpp 1つめのmodintにoperator==,!=を追加したものです thx @noshi91!! */ #line 14 "/home/imperi/cp-library/lib/utility/modint.hpp" template class modint { using u64 = std::uint_fast64_t; public: u64 a; constexpr modint(const u64 x = 0) noexcept : a(x % Modulus) {} constexpr u64 &value() noexcept { return a; } constexpr const u64 &value() const noexcept { return a; } constexpr bool operator==(const modint rhs) const noexcept { return a == rhs.a; } constexpr bool operator!=(const modint rhs) const noexcept { return !(*this == rhs); } constexpr modint operator+(const modint rhs) const noexcept { return modint(*this) += rhs; } constexpr modint operator-(const modint rhs) const noexcept { return modint(*this) -= rhs; } constexpr modint operator*(const modint rhs) const noexcept { return modint(*this) *= rhs; } constexpr modint operator/(const modint rhs) const noexcept { return modint(*this) /= rhs; } constexpr modint &operator+=(const modint rhs) noexcept { a += rhs.a; if (a >= Modulus) { a -= Modulus; } return *this; } constexpr modint &operator-=(const modint rhs) noexcept { if (a < rhs.a) { a += Modulus; } a -= rhs.a; return *this; } constexpr modint &operator*=(const modint rhs) noexcept { a = a * rhs.a % Modulus; return *this; } constexpr modint &operator/=(modint rhs) noexcept { u64 exp = Modulus - 2; while (exp) { if (exp % 2) { *this *= rhs; } rhs *= rhs; exp /= 2; } return *this; } }; #line 100 "main.cpp" constexpr u64 MOD = 998244353; using mint = modint; struct Monoid{ using value_t = std::pair; static constexpr value_t id = {0,0}; static constexpr value_t op(value_t a,value_t b){ return {a.first+b.first,a.second+b.second}; } }; #line 2 "/home/imperi/cp-library/lib/SegmentTree/DynamicSegmentTree.hpp" #line 5 "/home/imperi/cp-library/lib/SegmentTree/DynamicSegmentTree.hpp" // Monoid // type value_t // static var id // static (value_t,value_t)->value_t op template class DynamicSegmentTree { public: using value_t = typename Monoid::value_t; using size_t = std::size_t; private: struct Node { value_t val; Node *left, *right, *par; Node(Node* par_ = nullptr) : val(Monoid::id), left(), right(), par(par_) {} ~Node() { if (left) delete left; if (right) delete right; left = nullptr; right = nullptr; par = nullptr; } }; using node_ptr = Node*; size_t n, n0; node_ptr root; value_t fold(size_t a, size_t b, const node_ptr& now, size_t l, size_t r) { if (a <= l && r <= b) return now->val; if (b <= l || r <= a) return Monoid::id; value_t lval = (now->left) ? fold(a, b, now->left, l, l + (r - l) / 2) : Monoid::id; value_t rval = (now->right) ? fold(a, b, now->right, l + (r - l) / 2, r) : Monoid::id; return Monoid::op(lval, rval); } void copy_dfs(node_ptr& node, const node_ptr& from) { node->val = from->val; if (from->left) { node->left = new Node(node); copy_dfs(node->left, from->left); } if (from->right) { node->right = new Node(node); copy_dfs(node->right, from->right); } } public: DynamicSegmentTree(size_t n_ = 0) : n(n_), root(nullptr) { n0 = 1; while (n0 < n) n0 <<= 1; } DynamicSegmentTree(const DynamicSegmentTree& from) { n = from.n; n0 = from.n0; root = nullptr; if (from.root) { root = new Node(); copy_dfs(root, from.root); } } DynamicSegmentTree& operator=(const DynamicSegmentTree& from) { n = from.n; n0 = from.n0; root = nullptr; if (from.root) { root = new Node(); copy_dfs(root, from.root); } } DynamicSegmentTree(DynamicSegmentTree&&) = default; DynamicSegmentTree& operator=(DynamicSegmentTree&&) = default; ~DynamicSegmentTree() { if (root) delete root; root = nullptr; } void update(size_t i, value_t val, bool change) { assert(0 <= i && i < n); if (!root) root = new Node(); node_ptr now = root; size_t l = 0, r = n0; while (r - l > 1) { size_t mid = l + (r - l) / 2; if (i < mid) { if (!now->left) now->left = new Node(now); now = now->left; r = mid; } else { if (!now->right) now->right = new Node(now); now = now->right; l = mid; } } if (change) now->val = val; else now->val = Monoid::op(now->val, val); while (now->par) { now = now->par; now->val = Monoid::op((now->left) ? now->left->val : Monoid::id, (now->right) ? now->right->val : Monoid::id); } } value_t fold(size_t a, size_t b) { assert(0 <= a && a <= b && b <= n); if (!root) return Monoid::id; return fold(a, b, root, 0, n0); } }; #line 114 "main.cpp" int main() { std::cin.tie(nullptr); std::ios::sync_with_stdio(false); i64 n; std::cin>>n; std::vector a(n); for(auto&& e:a)std::cin>>e; std::reverse(all(a)); constexpr i64 INF = 1e10; DynamicSegmentTree seg1(INF),seg2(INF); std::vector left_sum(n,0),right_sum(n,0); std::vector left_cnt(n,1),right_cnt(n,1); rep(i,0,n){ auto tmp = seg1.fold(0,a[i]); left_sum[i] = tmp.first; left_cnt[i] = tmp.second; seg1.update(a[i],Monoid::value_t(a[i],1),false); } for(i64 i = n-1;i>=0;i--){ auto tmp = seg2.fold(a[i]+1,INF); right_sum[i] = tmp.first; right_cnt[i] = tmp.second; seg2.update(a[i],Monoid::value_t(a[i],1),false); } mint ans = 0; rep(i,0,n){ ans += left_sum[i] * right_cnt[i]; ans += right_sum[i] * left_cnt[i]; ans += left_cnt[i] * right_cnt[i] * a[i]; } rep(i,0,n){ debug(i,left_sum[i].value(),left_cnt[i].value()); } for(i64 i = n-1;i>=0;i--){ debug(i,right_sum[i].value(),right_cnt[i].value()); } std::cout<