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:heavy_check_mark: verify/number-theory/LC_sum_of_totient_function.test.cpp

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#define PROBLEM "https://judge.yosupo.jp/problem/sum_of_totient_function"

#include "template/template.hpp"
#include "modint/modint.hpp"
using mint = ModInt<998244353>;
#include "number-theory/totient-function.hpp"

int main() {
  ll n;
  in(n);
  out(TotientFunction::sum<mint>(n));
}
#line 1 "verify/number-theory/LC_sum_of_totient_function.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/sum_of_totient_function"

#line 2 "template/template.hpp"
#include <bits/stdc++.h>
using namespace std;

#line 2 "template/macro.hpp"
#define rep(i, a, b) for (int i = (a); i < (int)(b); i++)
#define rrep(i, a, b) for (int i = (int)(b) - 1; i >= (a); i--)
#define ALL(v) (v).begin(), (v).end()
#define UNIQUE(v) sort(ALL(v)), (v).erase(unique(ALL(v)), (v).end())
#define SZ(v) (int)v.size()
#define MIN(v) *min_element(ALL(v))
#define MAX(v) *max_element(ALL(v))
#define LB(v, x) int(lower_bound(ALL(v), (x)) - (v).begin())
#define UB(v, x) int(upper_bound(ALL(v), (x)) - (v).begin())
#define YN(b) cout << ((b) ? "YES" : "NO") << "\n";
#define Yn(b) cout << ((b) ? "Yes" : "No") << "\n";
#define yn(b) cout << ((b) ? "yes" : "no") << "\n";
#line 6 "template/template.hpp"

#line 2 "template/util.hpp"
using uint = unsigned int;
using ll = long long int;
using ull = unsigned long long;
using i128 = __int128_t;
using u128 = __uint128_t;
template <class T>
using priority_queue_asc = priority_queue<T, vector<T>, greater<T>>;

template <class T, class S = T>
S SUM(const vector<T>& a) {
  return accumulate(ALL(a), S(0));
}
template <class T1, class T2>
inline bool chmin(T1& a, T2 b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T1, class T2>
inline bool chmax(T1& a, T2 b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T1, class T2>
inline bool chmin_opt(optional<T1>& a, T2 b) {
  if (!a || a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T1, class T2>
inline bool chmax_opt(optional<T1>& a, T2 b) {
  if (!a || a < b) {
    a = b;
    return true;
  }
  return false;
}

template <class T>
int popcnt(T x) {
  return __builtin_popcountll(x);
}
template <class T>
int topbit(T x) {
  return (x == 0 ? -1 : 63 - __builtin_clzll(x));
}
template <class T>
int lowbit(T x) {
  return (x == 0 ? -1 : __builtin_ctzll(x));
}
#line 8 "template/template.hpp"

#line 2 "template/inout.hpp"
struct Fast {
  Fast() {
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
    cout << fixed << setprecision(15);
  }
} fast;

ostream& operator<<(ostream& os, __uint128_t x) {
  char buf[40];
  size_t k = 0;
  while (x > 0) buf[k++] = (char)(x % 10 + '0'), x /= 10;
  if (k == 0) buf[k++] = '0';
  while (k) os << buf[--k];
  return os;
}
ostream& operator<<(ostream& os, __int128_t x) {
  return x < 0 ? (os << '-' << (__uint128_t)(-x)) : (os << (__uint128_t)x);
}
template <class T, size_t N>
ostream& operator<<(ostream& os, const array<T, N>& a);
template <class T1, class T2>
istream& operator>>(istream& is, pair<T1, T2>& p) {
  return is >> p.first >> p.second;
}
template <class T1, class T2>
ostream& operator<<(ostream& os, const pair<T1, T2>& p) {
  return os << p.first << " " << p.second;
}
template <class T>
istream& operator>>(istream& is, vector<T>& a) {
  for (auto& v : a) is >> v;
  return is;
}
template <class T>
ostream& operator<<(ostream& os, const vector<T>& a) {
  for (auto it = a.begin(); it != a.end();) {
    os << *it;
    if (++it != a.end()) os << " ";
  }
  return os;
}
template <class T, size_t N>
ostream& operator<<(ostream& os, const array<T, N>& a) {
  for (auto it = a.begin(); it != a.end();) {
    os << *it;
    if (++it != a.end()) os << " ";
  }
  return os;
}
template <class T>
ostream& operator<<(ostream& os, const set<T>& st) {
  os << "{";
  for (auto it = st.begin(); it != st.end();) {
    os << *it;
    if (++it != st.end()) os << ",";
  }
  os << "}";
  return os;
}
template <class T1, class T2>
ostream& operator<<(ostream& os, const map<T1, T2>& mp) {
  os << "{";
  for (auto it = mp.begin(); it != mp.end();) {
    os << it->first << ":" << it->second;
    if (++it != mp.end()) os << ",";
  }
  os << "}";
  return os;
}

void in() {}
template <typename T, class... U>
void in(T& t, U&... u) {
  cin >> t;
  in(u...);
}
template <class... T>
void in_zip(int n, T&... t) {
  assert(n >= 0 && ((size(t) >= static_cast<size_t>(n)) && ...));
  for (int i = 0; i < n; i++) in(t[i]...);
}
void out() { cout << "\n"; }
template <typename T, class... U, char sep = ' '>
void out(const T& t, const U&... u) {
  cout << t;
  if (sizeof...(u)) cout << sep;
  out(u...);
}
template <class T, class U>
void out_opt(const optional<T>& opt, const U& fallback, ostream& os = cout) {
  if (opt.has_value())
    os << opt.value();
  else
    os << fallback;
  os << "\n";
}
template <class T, class U>
void out_opt(const vector<optional<T>>& vec, const U& fallback, ostream& os = cout) {
  for (auto it = vec.begin(); it != vec.end();) {
    if ((*it).has_value())
      os << (*it).value();
    else
      os << fallback;
    if (++it != vec.end()) os << " ";
  }
  os << "\n";
}

namespace IO {
template <class T, class... U>
T read(U&&... u) {
  T t = T(forward<U>(u)...);
  in(t);
  return t;
}
namespace Graph {
vector<vector<int>> unweighted(int n, int m, bool directed = false, int offset = 1) {
  vector<vector<int>> g(n);
  for (int i = 0; i < m; i++) {
    int u, v;
    cin >> u >> v;
    u -= offset, v -= offset;
    g[u].push_back(v);
    if (!directed) g[v].push_back(u);
  }
  return g;
}
template <class T>
vector<vector<pair<int, T>>> weighted(int n, int m, bool directed = false, int offset = 1) {
  vector<vector<pair<int, T>>> g(n);
  for (int i = 0; i < m; i++) {
    int u, v;
    T w;
    cin >> u >> v >> w;
    u -= offset, v -= offset;
    g[u].push_back({v, w});
    if (!directed) g[v].push_back({u, w});
  }
  return g;
}
}  // namespace Graph
namespace Tree {
vector<vector<int>> unweighted(int n, bool directed = false, int offset = 1) {
  return Graph::unweighted(n, n - 1, directed, offset);
}
template <class T>
vector<vector<pair<int, T>>> weighted(int n, bool directed = false, int offset = 1) {
  return Graph::weighted<T>(n, n - 1, directed, offset);
}
vector<vector<int>> rooted(int n, bool to_root = true, bool to_leaf = true, int offset = 1) {
  vector<vector<int>> g(n);
  for (int i = 1; i < n; i++) {
    int p;
    cin >> p;
    p -= offset;
    if (to_root) g[i].push_back(p);
    if (to_leaf) g[p].push_back(i);
  }
  return g;
}
}  // namespace Tree
}  // namespace IO
#line 10 "template/template.hpp"

#line 2 "template/debug.hpp"
#ifdef LOCAL
#define debug 1
#define show(...) _show(0, #__VA_ARGS__, __VA_ARGS__)
#else
#define debug 0
#define show(...) true
#endif
template <class T>
void _show(int, T) {
  cerr << '\n';
}
template <class T1, class T2, class... T3>
void _show(int i, const T1& a, const T2& b, const T3&... c) {
  for (; a[i] != ',' && a[i] != '\0'; i++) cerr << a[i];
  cerr << ":" << b << " ";
  _show(i + 1, a, c...);
}
#line 2 "math/util.hpp"

namespace Math {
template <class T>
T safe_mod(T a, T b) {
  assert(b != 0);
  if (b < 0) a = -a, b = -b;
  a %= b;
  return a >= 0 ? a : a + b;
}
template <class T>
T floor(T a, T b) {
  assert(b != 0);
  if (b < 0) a = -a, b = -b;
  return a >= 0 ? a / b : (a + 1) / b - 1;
}
template <class T>
T ceil(T a, T b) {
  assert(b != 0);
  if (b < 0) a = -a, b = -b;
  return a > 0 ? (a - 1) / b + 1 : a / b;
}
long long isqrt(long long n) {
  if (n <= 0) return 0;
  long long x = sqrt(n);
  while ((__int128)(x + 1) * (x + 1) <= n) x++;
  while ((__int128)x * x > n) x--;
  return x;
}
long long floor_root(long long n, int k) {
  assert(n >= 0);
  if (n == 0) return 0;
  assert(k >= 1);
  if (k == 1) return n;
  if (k > 64) return 1;
  long long x = round(pow((long double)n, 1.0L / k));
  auto check = [&](long long a) {
    if (a <= 0) return true;
    __int128_t p = 1;
    for (int i = 0; i < k; ++i)
      if ((p *= a) > n) return false;
    return true;
  };
  while (check(x + 1)) x++;
  while (!check(x)) x--;
  return x;
}
unsigned long long floor_root_unsigned(unsigned long long n, int k) {
  assert(k >= 1);
  if (n <= 1 || k == 1) return n;
  if (k >= 64) return 1;
  int bits = (64 + k - 1) / k;
  unsigned long long ok = 1, ng = min(n, 1ULL << bits);
  auto check = [&](unsigned long long a) {
    __uint128_t p = 1;
    for (int i = 0; i < k; i++) {
      p *= a;
      if (p > n) return false;
    }
    return true;
  };
  while (ok + 1 < ng) {
    unsigned long long mid = ok + (ng - ok) / 2;
    (check(mid) ? ok : ng) = mid;
  }
  return ok;
}
// return g=gcd(a,b)
// a*x+b*y=g
// - b!=0 -> 0<=x<|b|/g
// - b=0  -> ax=g
template <class T>
T ext_gcd(T a, T b, T& x, T& y) {
  T a0 = a, b0 = b;
  bool sgn_a = a < 0, sgn_b = b < 0;
  if (sgn_a) a = -a;
  if (sgn_b) b = -b;
  if (b == 0) {
    x = sgn_a ? -1 : 1;
    y = 0;
    return a;
  }
  T x00 = 1, x01 = 0, x10 = 0, x11 = 1;
  while (b != 0) {
    T q = a / b, r = a - b * q;
    x00 -= q * x01;
    x10 -= q * x11;
    swap(x00, x01);
    swap(x10, x11);
    a = b, b = r;
  }
  x = x00, y = x10;
  if (sgn_a) x = -x;
  if (sgn_b) y = -y;
  if (b0 != 0) {
    a0 /= a, b0 /= a;
    if (b0 < 0) a0 = -a0, b0 = -b0;
    T q = x >= 0 ? x / b0 : (x + 1) / b0 - 1;
    x -= b0 * q;
    y += a0 * q;
  }
  return a;
}
constexpr long long inv_mod(long long x, long long m) {
  x %= m;
  if (x < 0) x += m;
  long long a = m, b = x;
  long long y0 = 0, y1 = 1;
  while (b > 0) {
    long long q = a / b;
    swap(a -= q * b, b);
    swap(y0 -= q * y1, y1);
  }
  if (y0 < 0) y0 += m / a;
  return y0;
}
long long pow_mod(long long x, long long n, long long m) {
  if (m == 1) return 0;
  x = (x % m + m) % m;
  long long y = 1;
  while (n) {
    if (n & 1) y = y * x % m;
    x = x * x % m;
    n >>= 1;
  }
  return y;
}
constexpr long long pow_mod_constexpr(long long x, long long n, int m) {
  if (m == 1) return 0;
  unsigned int _m = (unsigned int)(m);
  unsigned long long r = 1;
  unsigned long long y = x % m;
  if (y >= m) y += m;
  while (n) {
    if (n & 1) r = (r * y) % _m;
    y = (y * y) % _m;
    n >>= 1;
  }
  return r;
}
constexpr bool is_prime_constexpr(int n) {
  if (n <= 1) return false;
  if (n == 2 || n == 7 || n == 61) return true;
  if (n % 2 == 0) return false;
  long long d = n - 1;
  while (d % 2 == 0) d /= 2;
  constexpr long long bases[3] = {2, 7, 61};
  for (long long a : bases) {
    long long t = d;
    long long y = pow_mod_constexpr(a, t, n);
    while (t != n - 1 && y != 1 && y != n - 1) {
      y = y * y % n;
      t <<= 1;
    }
    if (y != n - 1 && t % 2 == 0) {
      return false;
    }
  }
  return true;
}
template <int n>
constexpr bool is_prime = is_prime_constexpr(n);
};  // namespace Math
#line 3 "modint/modint.hpp"

template <unsigned int m = 998244353>
struct ModInt {
  using mint = ModInt;
  static constexpr unsigned int get_mod() { return m; }
  static mint raw(int v) {
    mint x;
    x._v = v;
    return x;
  }
  ModInt() : _v(0) {}
  ModInt(int64_t v) {
    long long x = (long long)(v % (long long)(umod()));
    if (x < 0) x += umod();
    _v = (unsigned int)(x);
  }
  unsigned int val() const { return _v; }
  mint& operator++() {
    _v++;
    if (_v == umod()) _v = 0;
    return *this;
  }
  mint& operator--() {
    if (_v == 0) _v = umod();
    _v--;
    return *this;
  }
  mint operator++(int) {
    mint result = *this;
    ++*this;
    return result;
  }
  mint operator--(int) {
    mint result = *this;
    --*this;
    return result;
  }
  mint& operator+=(const mint& rhs) {
    _v += rhs._v;
    if (_v >= umod()) _v -= umod();
    return *this;
  }
  mint& operator-=(const mint& rhs) {
    _v -= rhs._v;
    if (_v >= umod()) _v += umod();
    return *this;
  }
  mint& operator*=(const mint& rhs) {
    unsigned long long z = _v;
    z *= rhs._v;
    _v = (unsigned int)(z % umod());
    return *this;
  }
  mint& operator/=(const mint& rhs) { return *this *= rhs.inv(); }
  mint operator+() const { return *this; }
  mint operator-() const { return mint() - *this; }
  mint pow(long long n) const {
    assert(0 <= n);
    mint x = *this, r = 1;
    while (n) {
      if (n & 1) r *= x;
      x *= x;
      n >>= 1;
    }
    return r;
  }
  mint inv() const {
    if (is_prime) {
      assert(_v);
      return pow(umod() - 2);
    } else {
      auto inv = Math::inv_mod(_v, umod());
      return raw(inv);
    }
  }
  friend mint operator+(const mint& lhs, const mint& rhs) { return mint(lhs) += rhs; }
  friend mint operator-(const mint& lhs, const mint& rhs) { return mint(lhs) -= rhs; }
  friend mint operator*(const mint& lhs, const mint& rhs) { return mint(lhs) *= rhs; }
  friend mint operator/(const mint& lhs, const mint& rhs) { return mint(lhs) /= rhs; }
  friend bool operator==(const mint& lhs, const mint& rhs) { return lhs._v == rhs._v; }
  friend bool operator!=(const mint& lhs, const mint& rhs) { return lhs._v != rhs._v; }
  friend istream& operator>>(istream& is, mint& x) {
    int64_t v;
    is >> v;
    x = mint(v);
    return is;
  }
  friend ostream& operator<<(ostream& os, const mint& x) { return os << x.val(); }

 private:
  unsigned int _v;
  static constexpr unsigned int umod() { return m; }
  static constexpr bool is_prime = Math::is_prime<m>;
};
using ModInt998244353 = ModInt<998244353>;
using ModInt1000000007 = ModInt<1000000007>;
#line 5 "verify/number-theory/LC_sum_of_totient_function.test.cpp"
using mint = ModInt<998244353>;
#line 2 "number-theory/totient-function.hpp"

#line 2 "number-theory/prime-sieve.hpp"

namespace PrimeSieve {
using ll = long long;

vector<int> lpf(int n) {
  assert(n >= 0);
  vector<int> ret(n + 1);
  for (size_t i = 0; i < ret.size(); i++) ret[i] = (int)i;
  for (int p = 2; (ll)p * p <= n; p++) {
    if (ret[p] != p) continue;
    for (ll x = (ll)p * p;; x += p) {
      if (ret[x] == x) ret[x] = p;
      if (n - x < p) break;
    }
  }
  return ret;
}

vector<int> table(int n) {
  assert(n >= 0);
  vector<bool> composite(n + 1, false);
  for (int p = 2; (ll)p * p <= n; p += (p & 1) + 1) {
    if (composite[p]) continue;
    for (ll x = (ll)p * p;; x += p) {
      composite[x] = true;
      if (n - x < p) break;
    }
  }
  vector<int> ps;
  for (int p = 2; p <= n;) {
    if (!composite[p]) ps.push_back(p);
    int step = (p & 1) + 1;
    if (n - p < step) break;
    p += step;
  }
  return ps;
}

vector<vector<pair<ll, int>>> factorize(int n) {
  assert(n >= 0);
  vector<vector<pair<ll, int>>> factors(n + 1);
  auto lp = lpf(n);
  for (int x = 2; x <= n;) {
    int y = x;
    while (y > 1) {
      int p = lp[y], e = 0;
      while (y % p == 0) y /= p, e++;
      factors[x].emplace_back(p, e);
    }
    if (x == n) break;
    x++;
  }
  return factors;
}
};  // namespace PrimeSieve

/**
 * @brief 素数篩
 * @docs docs/number-theory/prime-sieve.md
 */
#line 4 "number-theory/totient-function.hpp"

namespace TotientFunction {
vector<int> table(int n) {
  vector<int> tot(n + 1, 1);
  tot[0] = 0;
  auto lpf = PrimeSieve::lpf(n);
  for (int x = 2; x <= n; x++) {
    int p = lpf[x];
    if (x / p % p == 0)
      tot[x] = tot[x / p] * p;
    else
      tot[x] = tot[x / p] * (p - 1);
  }
  return tot;
}
template <class T>
T sum(long long n) {
  const int lim = 2000000;
  if (n < lim) {
    vector<int> phi(n + 1);
    iota(phi.begin(), phi.end(), 0);
    vector<bool> f(n + 1, false);
    for (int i = 2; i <= n; i += (i & 1) + 1)
      if (!f[i])
        for (int j = i; j <= n; j += i) {
          f[j] = true;
          phi[j] -= phi[j] / i;
        }
    T ans = 0;
    for (auto v : phi) ans += v;
    return ans;
  } else {
    vector<T> sum_small(lim), sum_large(n / lim + 1);
    iota(sum_small.begin(), sum_small.end(), 0);
    vector<bool> f(lim, false);
    for (int i = 2; i < lim; i += (i & 1) + 1)
      if (!f[i])
        for (int j = i; j < lim; j += i) {
          f[j] = true;
          sum_small[j] -= sum_small[j] / i;
        }
    for (int i = 2; i < lim; i++) sum_small[i] += sum_small[i - 1];
    const int sz = sum_large.size();
    for (int k = sz - 1; k > 0; k--) {
      int m = 2;
      long long cur = n / k;
      sum_large[k] = (T)((cur + 1) / 2) * (cur | 1);
      for (; cur / m != cur / (m + 1) && m <= cur; m++)
        sum_large[k] -= k * m >= sz ? sum_small[cur / m] : sum_large[k * m];
      for (int arg = (int)(cur / m); arg >= 1; arg--)
        sum_large[k] -= (T)(cur / arg - cur / (arg + 1)) * (arg < lim ? sum_small[arg] : sum_large[n / arg]);
    }
    return sum_large[1];
  }
}
};  // namespace TotientFunction

/**
 * @brief Totient Function
 * @docs docs/number-theory/totient-function.md
 */
#line 7 "verify/number-theory/LC_sum_of_totient_function.test.cpp"

int main() {
  ll n;
  in(n);
  out(TotientFunction::sum<mint>(n));
}
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