// #pragma GCC target("avx2") // #pragma GCC optimize("O3") // #pragma GCC optimize("unroll-loops") // #define INTERACTIVE #include using namespace std; namespace templates { // type using ll = long long; using ull = unsigned long long; using Pii = pair; using Pil = pair; using Pli = pair; using Pll = pair; template using pq = priority_queue; template using qp = priority_queue, greater>; // clang-format off #define vec(T, A, ...) vector A(__VA_ARGS__); #define vvec(T, A, h, ...) vector> A(h, vector(__VA_ARGS__)); #define vvvec(T, A, h1, h2, ...) vector>> A(h1, vector>(h2, vector(__VA_ARGS__))); // clang-format on // for loop #define fori1(a) for (ll _ = 0; _ < (a); _++) #define fori2(i, a) for (ll i = 0; i < (a); i++) #define fori3(i, a, b) for (ll i = (a); i < (b); i++) #define fori4(i, a, b, c) for (ll i = (a); ((c) > 0 || i > (b)) && ((c) < 0 || i < (b)); i += (c)) #define overload4(a, b, c, d, e, ...) e #define fori(...) overload4(__VA_ARGS__, fori4, fori3, fori2, fori1)(__VA_ARGS__) // declare and input // clang-format off #define INT(...) int __VA_ARGS__; inp(__VA_ARGS__); #define LL(...) ll __VA_ARGS__; inp(__VA_ARGS__); #define STRING(...) string __VA_ARGS__; inp(__VA_ARGS__); #define CHAR(...) char __VA_ARGS__; inp(__VA_ARGS__); #define DOUBLE(...) double __VA_ARGS__; STRING(str___); __VA_ARGS__ = stod(str___); #define VEC(T, A, n) vector A(n); inp(A); #define VVEC(T, A, n, m) vector> A(n, vector(m)); inp(A); // clang-format on // const value const ll MOD1 = 1000000007; const ll MOD9 = 998244353; const double PI = acos(-1); // other macro #if !defined(RIN__LOCAL) && !defined(INTERACTIVE) #define endl "\n" #endif #define spa ' ' #define len(A) ll(A.size()) #define all(A) begin(A), end(A) // function vector stoc(string &S) { int n = S.size(); vector ret(n); for (int i = 0; i < n; i++) ret[i] = S[i]; return ret; } string ctos(vector &S) { int n = S.size(); string ret = ""; for (int i = 0; i < n; i++) ret += S[i]; return ret; } template auto min(const T &a) { return *min_element(all(a)); } template auto max(const T &a) { return *max_element(all(a)); } template auto clamp(T &a, const S &l, const S &r) { return (a > r ? r : a < l ? l : a); } template inline bool chmax(T &a, const S &b) { return (a < b ? a = b, 1 : 0); } template inline bool chmin(T &a, const S &b) { return (a > b ? a = b, 1 : 0); } template inline bool chclamp(T &a, const S &l, const S &r) { auto b = clamp(a, l, r); return (a != b ? a = b, 1 : 0); } template T sum(vector &A) { T tot = 0; for (auto a : A) tot += a; return tot; } template vector compression(vector X) { sort(all(X)); X.erase(unique(all(X)), X.end()); return X; } // input and output namespace io { // __int128_t std::ostream &operator<<(std::ostream &dest, __int128_t value) { std::ostream::sentry s(dest); if (s) { __uint128_t tmp = value < 0 ? -value : value; char buffer[128]; char *d = std::end(buffer); do { --d; *d = "0123456789"[tmp % 10]; tmp /= 10; } while (tmp != 0); if (value < 0) { --d; *d = '-'; } int len = std::end(buffer) - d; if (dest.rdbuf()->sputn(d, len) != len) { dest.setstate(std::ios_base::badbit); } } return dest; } // vector template istream &operator>>(istream &is, vector &A) { for (auto &a : A) is >> a; return is; } template ostream &operator<<(ostream &os, vector &A) { for (size_t i = 0; i < A.size(); i++) { os << A[i]; if (i != A.size() - 1) os << ' '; } return os; } // vector> template istream &operator>>(istream &is, vector> &A) { for (auto &a : A) is >> a; return is; } template ostream &operator<<(ostream &os, vector> &A) { for (size_t i = 0; i < A.size(); i++) { os << A[i]; if (i != A.size() - 1) os << endl; } return os; } // pair template istream &operator>>(istream &is, pair &A) { is >> A.first >> A.second; return is; } template ostream &operator<<(ostream &os, pair &A) { os << A.first << ' ' << A.second; return os; } // vector> template istream &operator>>(istream &is, vector> &A) { for (size_t i = 0; i < A.size(); i++) { is >> A[i]; } return is; } template ostream &operator<<(ostream &os, vector> &A) { for (size_t i = 0; i < A.size(); i++) { os << A[i]; if (i != A.size() - 1) os << endl; } return os; } // tuple template struct TuplePrint { static ostream &print(ostream &os, const T &t) { TuplePrint::print(os, t); os << ' ' << get(t); return os; } }; template struct TuplePrint { static ostream &print(ostream &os, const T &t) { os << get<0>(t); return os; } }; template ostream &operator<<(ostream &os, const tuple &t) { TuplePrint::print(os, t); return os; } // io functions void FLUSH() { cout << flush; } void print() { cout << endl; } template void print(Head &&head, Tail &&...tail) { cout << head; if (sizeof...(Tail)) cout << spa; print(std::forward(tail)...); } template void prisep(vector &A, S sep) { int n = A.size(); for (int i = 0; i < n; i++) { cout << A[i]; if (i != n - 1) cout << sep; } cout << endl; } template void priend(T A, S end) { cout << A << end; } template void prispa(T A) { priend(A, spa); } template bool printif(bool f, T A, S B) { if (f) print(A); else print(B); return f; } template void inp(T &...a) { (cin >> ... >> a); } } // namespace io using namespace io; // read graph vector> read_edges(int n, int m, bool direct = false, int indexed = 1) { vector> edges(n, vector()); for (int i = 0; i < m; i++) { INT(u, v); u -= indexed; v -= indexed; edges[u].push_back(v); if (!direct) edges[v].push_back(u); } return edges; } vector> read_tree(int n, int indexed = 1) { return read_edges(n, n - 1, false, indexed); } template vector>> read_wedges(int n, int m, bool direct = false, int indexed = 1) { vector>> edges(n, vector>()); for (int i = 0; i < m; i++) { INT(u, v); T w; inp(w); u -= indexed; v -= indexed; edges[u].push_back({v, w}); if (!direct) edges[v].push_back({u, w}); } return edges; } template vector>> read_wtree(int n, int indexed = 1) { return read_wedges(n, n - 1, false, indexed); } // yes / no namespace yesno { // yes inline bool yes(bool f = true) { cout << (f ? "yes" : "no") << endl; return f; } inline bool Yes(bool f = true) { cout << (f ? "Yes" : "No") << endl; return f; } inline bool YES(bool f = true) { cout << (f ? "YES" : "NO") << endl; return f; } // no inline bool no(bool f = true) { cout << (!f ? "yes" : "no") << endl; return f; } inline bool No(bool f = true) { cout << (!f ? "Yes" : "No") << endl; return f; } inline bool NO(bool f = true) { cout << (!f ? "YES" : "NO") << endl; return f; } // possible inline bool possible(bool f = true) { cout << (f ? "possible" : "impossible") << endl; return f; } inline bool Possible(bool f = true) { cout << (f ? "Possible" : "Impossible") << endl; return f; } inline bool POSSIBLE(bool f = true) { cout << (f ? "POSSIBLE" : "IMPOSSIBLE") << endl; return f; } // impossible inline bool impossible(bool f = true) { cout << (!f ? "possible" : "impossible") << endl; return f; } inline bool Impossible(bool f = true) { cout << (!f ? "Possible" : "Impossible") << endl; return f; } inline bool IMPOSSIBLE(bool f = true) { cout << (!f ? "POSSIBLE" : "IMPOSSIBLE") << endl; return f; } // Alice Bob inline bool Alice(bool f = true) { cout << (f ? "Alice" : "Bob") << endl; return f; } inline bool Bob(bool f = true) { cout << (f ? "Bob" : "Alice") << endl; return f; } // Takahashi Aoki inline bool Takahashi(bool f = true) { cout << (f ? "Takahashi" : "Aoki") << endl; return f; } inline bool Aoki(bool f = true) { cout << (f ? "Aoki" : "Takahashi") << endl; return f; } } // namespace yesno using namespace yesno; } // namespace templates using namespace templates; template struct Modint { int x; Modint() : x(0) {} Modint(int64_t y) { if (y >= 0) x = y % MOD; else x = (y % MOD + MOD) % MOD; } Modint &operator+=(const Modint &p) { x += p.x; if (x >= MOD) x -= MOD; return *this; } Modint &operator-=(const Modint &p) { x -= p.x; if (x < 0) x += MOD; return *this; } Modint &operator*=(const Modint &p) { x = int(1LL * x * p.x % MOD); return *this; } Modint &operator/=(const Modint &p) { *this *= p.inverse(); return *this; } Modint &operator%=(const Modint &p) { assert(p.x == 0); return *this; } Modint operator-() const { return Modint(-x); } Modint &operator++() { x++; if (x == MOD) x = 0; return *this; } Modint &operator--() { if (x == 0) x = MOD; x--; return *this; } Modint operator++(int) { Modint result = *this; ++*this; return result; } Modint operator--(int) { Modint result = *this; --*this; return result; } friend Modint operator+(const Modint &lhs, const Modint &rhs) { return Modint(lhs) += rhs; } friend Modint operator-(const Modint &lhs, const Modint &rhs) { return Modint(lhs) -= rhs; } friend Modint operator*(const Modint &lhs, const Modint &rhs) { return Modint(lhs) *= rhs; } friend Modint operator/(const Modint &lhs, const Modint &rhs) { return Modint(lhs) /= rhs; } friend Modint operator%(const Modint &lhs, const Modint &rhs) { assert(rhs.x == 0); return Modint(lhs); } bool operator==(const Modint &p) const { return x == p.x; } bool operator!=(const Modint &p) const { return x != p.x; } bool operator<(const Modint &rhs) const { return x < rhs.x; } bool operator<=(const Modint &rhs) const { return x <= rhs.x; } bool operator>(const Modint &rhs) const { return x > rhs.x; } bool operator>=(const Modint &rhs) const { return x >= rhs.x; } Modint inverse() const { int a = x, b = MOD, u = 1, v = 0, t; while (b > 0) { t = a / b; a -= t * b; u -= t * v; std::swap(a, b); std::swap(u, v); } return Modint(u); } Modint pow(int64_t k) const { Modint ret(1); Modint y(x); while (k > 0) { if (k & 1) ret *= y; y *= y; k >>= 1; } return ret; } std::pair to_frac(int max_n = 1000) const { int y = x; for (int i = 1; i <= max_n; i++) { if (y <= max_n) { return {y, i}; } else if (MOD - y <= max_n) { return {-(MOD - y), i}; } y = (y + x) % MOD; } return {-1, -1}; } friend std::ostream &operator<<(std::ostream &os, const Modint &p) { return os << p.x; } friend std::istream &operator>>(std::istream &is, Modint &p) { int64_t y; is >> y; p = Modint(y); return (is); } static int get_mod() { return MOD; } }; struct Arbitrary_Modint { int x; static int MOD; static void set_mod(int mod) { MOD = mod; } Arbitrary_Modint() : x(0) {} Arbitrary_Modint(int64_t y) { if (y >= 0) x = y % MOD; else x = (y % MOD + MOD) % MOD; } Arbitrary_Modint &operator+=(const Arbitrary_Modint &p) { x += p.x; if (x >= MOD) x -= MOD; return *this; } Arbitrary_Modint &operator-=(const Arbitrary_Modint &p) { x -= p.x; if (x < 0) x += MOD; return *this; } Arbitrary_Modint &operator*=(const Arbitrary_Modint &p) { x = int(1LL * x * p.x % MOD); return *this; } Arbitrary_Modint &operator/=(const Arbitrary_Modint &p) { *this *= p.inverse(); return *this; } Arbitrary_Modint &operator%=(const Arbitrary_Modint &p) { assert(p.x == 0); return *this; } Arbitrary_Modint operator-() const { return Arbitrary_Modint(-x); } Arbitrary_Modint &operator++() { x++; if (x == MOD) x = 0; return *this; } Arbitrary_Modint &operator--() { if (x == 0) x = MOD; x--; return *this; } Arbitrary_Modint operator++(int) { Arbitrary_Modint result = *this; ++*this; return result; } Arbitrary_Modint operator--(int) { Arbitrary_Modint result = *this; --*this; return result; } friend Arbitrary_Modint operator+(const Arbitrary_Modint &lhs, const Arbitrary_Modint &rhs) { return Arbitrary_Modint(lhs) += rhs; } friend Arbitrary_Modint operator-(const Arbitrary_Modint &lhs, const Arbitrary_Modint &rhs) { return Arbitrary_Modint(lhs) -= rhs; } friend Arbitrary_Modint operator*(const Arbitrary_Modint &lhs, const Arbitrary_Modint &rhs) { return Arbitrary_Modint(lhs) *= rhs; } friend Arbitrary_Modint operator/(const Arbitrary_Modint &lhs, const Arbitrary_Modint &rhs) { return Arbitrary_Modint(lhs) /= rhs; } friend Arbitrary_Modint operator%(const Arbitrary_Modint &lhs, const Arbitrary_Modint &rhs) { assert(rhs.x == 0); return Arbitrary_Modint(lhs); } bool operator==(const Arbitrary_Modint &p) const { return x == p.x; } bool operator!=(const Arbitrary_Modint &p) const { return x != p.x; } bool operator<(const Arbitrary_Modint &rhs) { return x < rhs.x; } bool operator<=(const Arbitrary_Modint &rhs) { return x <= rhs.x; } bool operator>(const Arbitrary_Modint &rhs) { return x > rhs.x; } bool operator>=(const Arbitrary_Modint &rhs) { return x >= rhs.x; } Arbitrary_Modint inverse() const { int a = x, b = MOD, u = 1, v = 0, t; while (b > 0) { t = a / b; a -= t * b; u -= t * v; std::swap(a, b); std::swap(u, v); } return Arbitrary_Modint(u); } Arbitrary_Modint pow(int64_t k) const { Arbitrary_Modint ret(1); Arbitrary_Modint y(x); while (k > 0) { if (k & 1) ret *= y; y *= y; k >>= 1; } return ret; } friend std::ostream &operator<<(std::ostream &os, const Arbitrary_Modint &p) { return os << p.x; } friend std::istream &operator>>(std::istream &is, Arbitrary_Modint &p) { int64_t y; is >> y; p = Arbitrary_Modint(y); return (is); } static int get_mod() { return MOD; } }; int Arbitrary_Modint::MOD = 998244353; using modint9 = Modint<998244353>; using modint1 = Modint<1000000007>; using modint = Arbitrary_Modint; using mint = modint9; template struct lazy_segtree { public: explicit lazy_segtree(const std::vector &v) : _n(int(v.size())) { size = 1; log = 0; while (size < _n) { log++; size <<= 1; } d = std::vector(2 * size, e()); lz = std::vector(size, id()); for (int i = 0; i < _n; i++) d[size + i] = v[i]; for (int i = size - 1; i >= 1; i--) update(i); } explicit lazy_segtree(int n) : lazy_segtree(std::vector(n, e())) {} S prod(int l, int r) { if (l == r) return e(); l += size; r += size; for (int i = log; i >= 1; i--) { if (((l >> i) << i) != l) push(l >> i); if (((r >> i) << i) != r) push((r - 1) >> i); } S sml = e(), smr = e(); while (l < r) { if (l & 1) sml = op(sml, d[l++]); if (r & 1) smr = op(d[--r], smr); l >>= 1; r >>= 1; } return op(sml, smr); } S get(int x) { return prod(x, x + 1); } S all_prod() { return d[1]; } void apply(int l, int r, F f) { if (l == r) return; l += size; r += size; for (int i = log; i >= 1; i--) { if (((l >> i) << i) != l) push(l >> i); if (((r >> i) << i) != r) push((r - 1) >> i); } { int l2 = l, r2 = r; while (l < r) { if (l & 1) all_apply(l++, f); if (r & 1) all_apply(--r, f); l >>= 1; r >>= 1; } l = l2; r = r2; } for (int i = 1; i <= log; i++) { if (((l >> i) << i) != l) update(l >> i); if (((r >> i) << i) != r) update((r - 1) >> i); } } private: int _n, size, log; std::vector d; std::vector lz; void update(int k) { d[k] = op(d[2 * k], d[2 * k + 1]); } void all_apply(int k, F f) { d[k] = mapping(f, d[k]); if (k < size) lz[k] = composition(f, lz[k]); } void push(int k) { all_apply(2 * k, lz[k]); all_apply(2 * k + 1, lz[k]); lz[k] = id(); } }; struct S { int le; mint prod; mint ma_tot; mint mi_tot; }; S op(S l, S r) { return {l.le + r.le, l.prod + r.prod, l.ma_tot + r.ma_tot, l.mi_tot + r.mi_tot}; }; S e() { return {0, 0, 0, 0}; }; struct F { mint ma_add; mint mi_add; }; S mapping(F f, S x) { return {x.le, x.prod + f.ma_add * x.mi_tot + f.mi_add * x.ma_tot + f.ma_add * f.mi_add * x.le, x.ma_tot + f.ma_add * x.le, x.mi_tot + f.mi_add * x.le}; }; F composition(F f, F g) { return {f.ma_add + g.ma_add, f.mi_add + g.mi_add}; }; F id() { return {0, 0}; }; void solve() { INT(n); VEC(ll, A, n); mint ans = 0; lazy_segtree seg(vector(n, {1, 0, 0, 0})); stack low; stack upp; low.push({(1LL << 60), -1}); upp.push({-(1LL << 60), -1}); fori(i, n) { ll a = A[i]; while (!low.empty() and low.top().first < a) { auto [b, r] = low.top(); low.pop(); auto l = low.top().second; seg.apply(l + 1, r + 1, {a - b, 0}); } low.push({a, i}); while (!upp.empty() and upp.top().first > a) { auto [b, r] = upp.top(); upp.pop(); auto l = upp.top().second; seg.apply(l + 1, r + 1, {0, a - b}); } upp.push({a, i}); seg.apply(i, i + 1, {a, a}); ans += seg.all_prod().prod; } print(ans); } int main() { #ifndef INTERACTIVE std::cin.tie(0)->sync_with_stdio(0); #endif // std::cout << std::fixed << std::setprecision(12); int t; t = 1; // std::cin >> t; while (t--) solve(); return 0; } // // #pragma GCC target("avx2") // // #pragma GCC optimize("O3") // // #pragma GCC optimize("unroll-loops") // // #define INTERACTIVE // // #include "kyopro-cpp/template.hpp" // // #include "misc/Modint.hpp" // using mint = modint9; // // #include "data_structure/lazySegTree.hpp" // // struct S { // int le; // mint prod; // mint ma_tot; // mint mi_tot; // }; // S op(S l, S r) { // return {l.le + r.le, l.prod + r.prod, l.ma_tot + r.ma_tot, l.mi_tot + r.mi_tot}; // }; // S e() { // return {0, 0, 0, 0}; // }; // struct F { // mint ma_add; // mint mi_add; // }; // S mapping(F f, S x) { // return {x.le, x.prod + f.ma_add * x.mi_tot + f.mi_add * x.ma_tot + f.ma_add * f.mi_add * // x.le, // x.ma_tot + f.ma_add * x.le, x.mi_tot + f.mi_add * x.le}; // }; // F composition(F f, F g) { // return {f.ma_add + g.ma_add, f.mi_add + g.mi_add}; // }; // F id() { // return {0, 0}; // }; // // void solve() { // INT(n); // VEC(ll, A, n); // mint ans = 0; // lazy_segtree seg(vector(n, {1, 0, 0, 0})); // // stack low; // stack upp; // // low.push({(1LL << 60), -1}); // upp.push({-(1LL << 60), -1}); // // fori(i, n) { // ll a = A[i]; // while (!low.empty() and low.top().first < a) { // auto [b, r] = low.top(); // low.pop(); // auto l = low.top().second; // seg.apply(l + 1, r + 1, {a - b, 0}); // } // low.push({a, i}); // while (!upp.empty() and upp.top().first > a) { // auto [b, r] = upp.top(); // upp.pop(); // auto l = upp.top().second; // seg.apply(l + 1, r + 1, {0, a - b}); // } // upp.push({a, i}); // // seg.apply(i, i + 1, {a, a}); // ans += seg.all_prod().prod; // } // print(ans); // } // // int main() { // #ifndef INTERACTIVE // std::cin.tie(0)->sync_with_stdio(0); // #endif // // std::cout << std::fixed << std::setprecision(12); // int t; // t = 1; // // std::cin >> t; // while (t--) solve(); // return 0; // }