Problem p02793 (C++)

Buggy submission (status: Runtime Error):
//{{{
#include <bits/stdc++.h>
using namespace std;

#define repX(a, b, c, x, ...) x
#define repN(a) repX a
#define rep(...) repN((__VA_ARGS__, rep3, rep2, loop))(__VA_ARGS__)
#define rrep(...) repN((__VA_ARGS__, rrep3, rrep2))(__VA_ARGS__)
#define loop(n) rep2(i_, n)
#define rep2(i, n) rep3(i, 0, n)
#define rep3(i, begin, end)                                                    \
  for (ll i = (ll)(begin), i##_end = (ll)(end); i < i##_end; ++i)
#define rrep2(i, n) rrep3(i, 0, n)
#define rrep3(i, begin, end)                                                   \
  for (ll i = (ll)(end - 1), i##_end = (ll)(begin); i >= i##_end; --i)
#define each(x, a) for (auto &x : a)
#define sz(x) ((ll)(x).size())

struct IoSetup {
  IoSetup() {
    cin.tie(nullptr);
    // ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
    cerr << fixed << setprecision(10);
  };
} ioSetup;

using ull = unsigned long long;
using ll = long long;
using pii = pair<ll, ll>;
using vp = vector<pii>;
using vs = vector<string>;
using vi = vector<ll>;
using vvi = vector<vi>;
#define v(T) vector<T>
#define vv(T) v(v(T))

template <class T, class U>
ostream &operator<<(ostream &o, const pair<T, U> &j) {
  o << "{" << j.first << ", " << j.second << "}";
  return o;
}
template <class T, class U>
ostream &operator<<(ostream &o, const map<T, U> &j) {
  o << "{";
  for (auto t = j.begin(); t != j.end(); ++t)
    o << (t != j.begin() ? ", " : "") << *t;
  o << "}";
  return o;
}
template <class T> ostream &operator<<(ostream &o, const set<T> &j) {
  o << "{";
  for (auto t = j.begin(); t != j.end(); ++t)
    o << (t != j.begin() ? ", " : "") << *t;
  o << "}";
  return o;
}
template <class T> ostream &operator<<(ostream &o, const multiset<T> &j) {
  o << "{";
  for (auto t = j.begin(); t != j.end(); ++t)
    o << (t != j.begin() ? ", " : "") << *t;
  o << "}";
  return o;
}
template <class T> ostream &operator<<(ostream &o, const vector<T> &j) {
  o << "{";
  for (ll i = 0; i < (ll)j.size(); ++i)
    o << (i > 0 ? ", " : "") << j[i];
  o << "}";
  return o;
}

template <class T, class Compare> inline void sort(T &a, Compare comp) {
  sort(a.begin(), a.end(), comp);
}
template <class T> inline void sort(T &a) { sort(a.begin(), a.end()); }
template <class T> inline void rsort(T &a) { sort(a.rbegin(), a.rend()); }
template <class T> inline void reverse(T &a) { reverse(a.begin(), a.end()); }
template <class T> inline bool next_permutation(T &a) {
  return next_permutation(a.begin(), a.end());
}
template <class T, class U> inline bool binary_search(T &a, const U &v) {
  return binary_search(a.begin(), a.end(), v);
}
template <class T, class U> inline auto lower_bound(T &a, const U &v) {
  return lower_bound(a.begin(), a.end(), v);
}
template <class T, class U> inline auto upper_bound(T &a, const U &v) {
  return upper_bound(a.begin(), a.end(), v);
}
template <class T> inline T Sum(vector<T> &a) {
  return accumulate(a.begin(), a.end(), (T)0);
}
template <class T> inline T Max(vector<T> &a) {
  return *max_element(a.begin(), a.end());
}
template <class T> inline T Min(vector<T> &a) {
  return *min_element(a.begin(), a.end());
}

template <class T, class U> inline bool chmax(T &a, const U &b) {
  return (b > a) ? (a = b, true) : false;
}
template <class T, class U> inline bool chmin(T &a, const U &b) {
  return (b < a) ? (a = b, true) : false;
}

ll gcd(const ll a, const ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(const ll a, const ll b) { return a / gcd(a, b) * b; }
ll ceil(const ll a, const ll b) { return (a + b - 1) / b; }

class in {
  int n, m;

public:
  in() : n(0), m(0) {}
  in(int n_) : n(n_), m(0){};
  in(int n_, int m_) : n(n_), m(m_){};
  template <class T> operator T() {
    assert(n == 0);
    assert(m == 0);
    T ret;
    cin >> ret;
    return ret;
  }
  template <class T> operator vector<T>() {
    assert(n > 0);
    assert(m == 0);
    vector<T> ret(n);
    for (ll i = 0; i < (ll)n; ++i)
      cin >> ret[i];
    return ret;
  }
  template <class T> operator vector<vector<T>>() {
    assert(n > 0);
    assert(m > 0);
    vector<vector<T>> ret(n, vector<T>(m));
    for (ll i = 0; i < (ll)n; ++i)
      for (ll j = 0; j < (ll)m; ++j)
        cin >> ret[i][j];
    return ret;
  }
};

template <class T> void print(const T &a) { cout << a; }
inline int out() {
  cout << '\n';
  return 0;
}
template <class T> inline int out(const T &t) {
  print(t);
  cout << '\n';
  return 0;
}
template <class Head, class... Tail>
inline int out(const Head &head, const Tail &...tail) {
  print(head);
  cout << " ";
  out(tail...);
  return 0;
}

#ifdef LOCAL
#include "console_color.hpp"
template <class T> void debug_print(const T &a) { cerr << a; }
inline void dump() {
  setColor();
  cerr << " \n";
}
template <class T> inline void dump(const T &t) {
  debug_print(t);
  setColor();
  cerr << " \n";
}
template <class Head, class... Tail>
inline void dump(const Head &head, const Tail &...tail) {
  setColor(COL_WHITE, COL_DARK_YELLOW);
  debug_print(head);
  cerr << " ";
  dump(tail...);
}
#define debug(...)                                                             \
  do {                                                                         \
    setColor(COL_WHITE, COL_DARK_BLUE);                                        \
    cerr << "[L." << __LINE__ << "] " << #__VA_ARGS__ << ": ";                 \
    setColor(COL_WHITE, COL_DARK_YELLOW);                                      \
    dump(__VA_ARGS__);                                                         \
  } while (0)
#else
#define dump(...)
#define debug(...)
#endif

template <class T> vector<T> make_vector(size_t a) { return vector<T>(a); }
template <class T, class... Tail> auto make_vector(size_t a, Tail... tail) {
  return vector<decltype(make_vector<T>(tail...))>(a, make_vector<T>(tail...));
}
#define Vector make_vector<ll>

template <std::int_fast64_t Mod> class Modular {
  using u64 = std::uint_fast64_t;

public:
  u64 a;
  constexpr Modular(std::int_fast64_t x = 0) noexcept
      : a(x % Mod + (x < 0 ? Mod : 0)) {}
  constexpr u64 val() const noexcept { return a; }
  constexpr Modular operator+(const Modular rhs) const noexcept {
    return Modular(*this) += rhs;
  }
  constexpr Modular operator-(const Modular rhs) const noexcept {
    return Modular(*this) -= rhs;
  }
  constexpr Modular operator*(const Modular rhs) const noexcept {
    return Modular(*this) *= rhs;
  }
  constexpr Modular operator/(const Modular rhs) const noexcept {
    return Modular(*this) /= rhs;
  }
  constexpr bool operator==(const Modular rhs) const noexcept {
    return Modular(*this).val() == rhs.val();
  }
  Modular &operator+=(const Modular rhs) noexcept {
    a += rhs.a;
    if (a >= Mod)
      a -= Mod;
    return *this;
  }
  Modular &operator-=(const Modular rhs) noexcept {
    if (a < rhs.a)
      a += Mod;
    a -= rhs.a;
    return *this;
  }
  Modular &operator++() noexcept { return *this += 1; }
  Modular &operator--() noexcept { return *this -= 1; }
  Modular &operator*=(const Modular rhs) noexcept {
    a = a * rhs.a % Mod;
    return *this;
  }
  Modular &operator/=(Modular rhs) noexcept {
    u64 exp = Mod - 2;
    while (exp) {
      if (exp % 2)
        *this *= rhs;
      rhs *= rhs;
      exp /= 2;
    }
    return *this;
  }
};
template <std::int_fast64_t Mod>
ostream &operator<<(ostream &os, const Modular<Mod> &m) {
  return os << m.a;
}

const double pi = acos(-1);
const double eps = 1e-9;
const ll inf = 1001001001;
const ll mod = (ll)1e9 + 7;
using mint = Modular<mod>;
//}}}

ll modpow(ll a, ll b) {
  ll res = 1;
  while (b > 0) {
    if (b & 1)
      res = res * a % mod;
    b >>= 1;
    a = a * a % mod;
  }
  return res;
}

int main() {
  ll N = in();
  vi A = in(N);
  map<ll, ll> mp;

  // N以下の素数を要素に持つ vector<int> を返します。
  auto Primes = [](int N) {
    vi res;
    vector<bool> f(N + 1);
    for (int i = 2; i * i <= N; ++i) {
      for (int t = 2 * i; t <= N; t += i)
        f[t] = true;
    }
    rep(i, 2, N + 1) if (!f[i]) res.push_back(i);
    return res;
  };
  vi primes = Primes(1000);
  // debug(primes);

  rep(n, N) {
    ll a = A[n];
    ll i = 0;
    while (1) {
      ll p = primes[i++];
      if (p * p > A[n])
        break;
      if (a % p == 0) {
        ll cnt = 0;
        while (a % p == 0) {
          a /= p;
          cnt++;
        }
        chmax(mp[p], cnt);
      }
    }
    if (a != 1)
      chmax(mp[a], 1);
  }

  // debug(mp);
  mint ans = 0;
  mint lc = 1;
  each(x, mp) {
    ll p = x.first;
    ll cnt = x.second;
    lc *= modpow(p, cnt);
  }
  debug(lc);

  rep(i, N) {
    ll a = A[i];
    mint add = lc;
    add /= a;
    ans += add;
  }
  out(ans);
}


Fixed submission:
//{{{
#include <bits/stdc++.h>
using namespace std;

#define repX(a, b, c, x, ...) x
#define repN(a) repX a
#define rep(...) repN((__VA_ARGS__, rep3, rep2, loop))(__VA_ARGS__)
#define rrep(...) repN((__VA_ARGS__, rrep3, rrep2))(__VA_ARGS__)
#define loop(n) rep2(i_, n)
#define rep2(i, n) rep3(i, 0, n)
#define rep3(i, begin, end)                                                    \
  for (ll i = (ll)(begin), i##_end = (ll)(end); i < i##_end; ++i)
#define rrep2(i, n) rrep3(i, 0, n)
#define rrep3(i, begin, end)                                                   \
  for (ll i = (ll)(end - 1), i##_end = (ll)(begin); i >= i##_end; --i)
#define each(x, a) for (auto &x : a)
#define sz(x) ((ll)(x).size())

struct IoSetup {
  IoSetup() {
    cin.tie(nullptr);
    // ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
    cerr << fixed << setprecision(10);
  };
} ioSetup;

using ull = unsigned long long;
using ll = long long;
using pii = pair<ll, ll>;
using vp = vector<pii>;
using vs = vector<string>;
using vi = vector<ll>;
using vvi = vector<vi>;
#define v(T) vector<T>
#define vv(T) v(v(T))

template <class T, class U>
ostream &operator<<(ostream &o, const pair<T, U> &j) {
  o << "{" << j.first << ", " << j.second << "}";
  return o;
}
template <class T, class U>
ostream &operator<<(ostream &o, const map<T, U> &j) {
  o << "{";
  for (auto t = j.begin(); t != j.end(); ++t)
    o << (t != j.begin() ? ", " : "") << *t;
  o << "}";
  return o;
}
template <class T> ostream &operator<<(ostream &o, const set<T> &j) {
  o << "{";
  for (auto t = j.begin(); t != j.end(); ++t)
    o << (t != j.begin() ? ", " : "") << *t;
  o << "}";
  return o;
}
template <class T> ostream &operator<<(ostream &o, const multiset<T> &j) {
  o << "{";
  for (auto t = j.begin(); t != j.end(); ++t)
    o << (t != j.begin() ? ", " : "") << *t;
  o << "}";
  return o;
}
template <class T> ostream &operator<<(ostream &o, const vector<T> &j) {
  o << "{";
  for (ll i = 0; i < (ll)j.size(); ++i)
    o << (i > 0 ? ", " : "") << j[i];
  o << "}";
  return o;
}

template <class T, class Compare> inline void sort(T &a, Compare comp) {
  sort(a.begin(), a.end(), comp);
}
template <class T> inline void sort(T &a) { sort(a.begin(), a.end()); }
template <class T> inline void rsort(T &a) { sort(a.rbegin(), a.rend()); }
template <class T> inline void reverse(T &a) { reverse(a.begin(), a.end()); }
template <class T> inline bool next_permutation(T &a) {
  return next_permutation(a.begin(), a.end());
}
template <class T, class U> inline bool binary_search(T &a, const U &v) {
  return binary_search(a.begin(), a.end(), v);
}
template <class T, class U> inline auto lower_bound(T &a, const U &v) {
  return lower_bound(a.begin(), a.end(), v);
}
template <class T, class U> inline auto upper_bound(T &a, const U &v) {
  return upper_bound(a.begin(), a.end(), v);
}
template <class T> inline T Sum(vector<T> &a) {
  return accumulate(a.begin(), a.end(), (T)0);
}
template <class T> inline T Max(vector<T> &a) {
  return *max_element(a.begin(), a.end());
}
template <class T> inline T Min(vector<T> &a) {
  return *min_element(a.begin(), a.end());
}

template <class T, class U> inline bool chmax(T &a, const U &b) {
  return (b > a) ? (a = b, true) : false;
}
template <class T, class U> inline bool chmin(T &a, const U &b) {
  return (b < a) ? (a = b, true) : false;
}

ll gcd(const ll a, const ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(const ll a, const ll b) { return a / gcd(a, b) * b; }
ll ceil(const ll a, const ll b) { return (a + b - 1) / b; }

class in {
  int n, m;

public:
  in() : n(0), m(0) {}
  in(int n_) : n(n_), m(0){};
  in(int n_, int m_) : n(n_), m(m_){};
  template <class T> operator T() {
    assert(n == 0);
    assert(m == 0);
    T ret;
    cin >> ret;
    return ret;
  }
  template <class T> operator vector<T>() {
    assert(n > 0);
    assert(m == 0);
    vector<T> ret(n);
    for (ll i = 0; i < (ll)n; ++i)
      cin >> ret[i];
    return ret;
  }
  template <class T> operator vector<vector<T>>() {
    assert(n > 0);
    assert(m > 0);
    vector<vector<T>> ret(n, vector<T>(m));
    for (ll i = 0; i < (ll)n; ++i)
      for (ll j = 0; j < (ll)m; ++j)
        cin >> ret[i][j];
    return ret;
  }
};

template <class T> void print(const T &a) { cout << a; }
inline int out() {
  cout << '\n';
  return 0;
}
template <class T> inline int out(const T &t) {
  print(t);
  cout << '\n';
  return 0;
}
template <class Head, class... Tail>
inline int out(const Head &head, const Tail &...tail) {
  print(head);
  cout << " ";
  out(tail...);
  return 0;
}

#ifdef LOCAL
#include "console_color.hpp"
template <class T> void debug_print(const T &a) { cerr << a; }
inline void dump() {
  setColor();
  cerr << " \n";
}
template <class T> inline void dump(const T &t) {
  debug_print(t);
  setColor();
  cerr << " \n";
}
template <class Head, class... Tail>
inline void dump(const Head &head, const Tail &...tail) {
  setColor(COL_WHITE, COL_DARK_YELLOW);
  debug_print(head);
  cerr << " ";
  dump(tail...);
}
#define debug(...)                                                             \
  do {                                                                         \
    setColor(COL_WHITE, COL_DARK_BLUE);                                        \
    cerr << "[L." << __LINE__ << "] " << #__VA_ARGS__ << ": ";                 \
    setColor(COL_WHITE, COL_DARK_YELLOW);                                      \
    dump(__VA_ARGS__);                                                         \
  } while (0)
#else
#define dump(...)
#define debug(...)
#endif

template <class T> vector<T> make_vector(size_t a) { return vector<T>(a); }
template <class T, class... Tail> auto make_vector(size_t a, Tail... tail) {
  return vector<decltype(make_vector<T>(tail...))>(a, make_vector<T>(tail...));
}
#define Vector make_vector<ll>

template <std::int_fast64_t Mod> class Modular {
  using u64 = std::uint_fast64_t;

public:
  u64 a;
  constexpr Modular(std::int_fast64_t x = 0) noexcept
      : a(x % Mod + (x < 0 ? Mod : 0)) {}
  constexpr u64 val() const noexcept { return a; }
  constexpr Modular operator+(const Modular rhs) const noexcept {
    return Modular(*this) += rhs;
  }
  constexpr Modular operator-(const Modular rhs) const noexcept {
    return Modular(*this) -= rhs;
  }
  constexpr Modular operator*(const Modular rhs) const noexcept {
    return Modular(*this) *= rhs;
  }
  constexpr Modular operator/(const Modular rhs) const noexcept {
    return Modular(*this) /= rhs;
  }
  constexpr bool operator==(const Modular rhs) const noexcept {
    return Modular(*this).val() == rhs.val();
  }
  Modular &operator+=(const Modular rhs) noexcept {
    a += rhs.a;
    if (a >= Mod)
      a -= Mod;
    return *this;
  }
  Modular &operator-=(const Modular rhs) noexcept {
    if (a < rhs.a)
      a += Mod;
    a -= rhs.a;
    return *this;
  }
  Modular &operator++() noexcept { return *this += 1; }
  Modular &operator--() noexcept { return *this -= 1; }
  Modular &operator*=(const Modular rhs) noexcept {
    a = a * rhs.a % Mod;
    return *this;
  }
  Modular &operator/=(Modular rhs) noexcept {
    u64 exp = Mod - 2;
    while (exp) {
      if (exp % 2)
        *this *= rhs;
      rhs *= rhs;
      exp /= 2;
    }
    return *this;
  }
};
template <std::int_fast64_t Mod>
ostream &operator<<(ostream &os, const Modular<Mod> &m) {
  return os << m.a;
}

const double pi = acos(-1);
const double eps = 1e-9;
const ll inf = 1001001001;
const ll mod = (ll)1e9 + 7;
using mint = Modular<mod>;
//}}}

ll modpow(ll a, ll b) {
  ll res = 1;
  while (b > 0) {
    if (b & 1)
      res = res * a % mod;
    b >>= 1;
    a = a * a % mod;
  }
  return res;
}

int main() {
  ll N = in();
  vi A = in(N);
  map<ll, ll> mp;

  // N以下の素数を要素に持つ vector<int> を返します。
  auto Primes = [](int N) {
    vi res;
    vector<bool> f(N + 1);
    for (int i = 2; i * i <= N; ++i) {
      for (int t = 2 * i; t <= N; t += i)
        f[t] = true;
    }
    rep(i, 2, N + 1) if (!f[i]) res.push_back(i);
    return res;
  };
  vi primes = Primes(2000);
  // debug(primes);

  rep(n, N) {
    ll a = A[n];
    ll i = 0;
    while (1) {
      ll p = primes[i++];
      if (p * p > A[n])
        break;
      if (a % p == 0) {
        ll cnt = 0;
        while (a % p == 0) {
          a /= p;
          cnt++;
        }
        chmax(mp[p], cnt);
      }
    }
    if (a != 1)
      chmax(mp[a], 1);
  }

  // debug(mp);
  mint ans = 0;
  mint lc = 1;
  each(x, mp) {
    ll p = x.first;
    ll cnt = x.second;
    lc *= modpow(p, cnt);
  }
  debug(lc);

  rep(i, N) {
    ll a = A[i];
    mint add = lc;
    add /= a;
    ans += add;
  }
  out(ans);
}