Problem p02793 (C++)

Buggy submission (status: Time Limit Exceeded):
#include <algorithm> // min, max, swap, sort, reverse, lower_bound, upper_bound
#include <bitset>    // bitset
#include <cctype>    // isupper, islower, isdigit, toupper, tolower
#include <cmath>
#include <cstdint>  // int64_t, int*_t
#include <cstdio>   // printf
#include <deque>    // deque
#include <iostream> // cout, endl, cin
#include <map>      // map
#include <math.h>
#include <queue> // queue, priority_queue
#include <set>   // set
#include <stack> // stack
#include <stdlib.h>
#include <string>        // string, to_string, stoi
#include <tuple>         // tuple, make_tuple
#include <unordered_map> // unordered_map
#include <unordered_set> // unordered_set
#include <utility>       // pair, make_pair
#include <vector>        // vector

using namespace std;

#define int long long
#define endl "\n"
#define all(v) v.begin(), v.end()
#define fir first
#define sec second
#define m_p make_pair
#define m_t make_tuple
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

const double pai = 3.1415926535897;
const int mod = 1000000007;
const int INF = 2000000015;
const int MAX = 510000;
const int MOD = 1000000007;
long long fac[MAX], finv[MAX], inv[MAX];

int jousu(int x00, int y00) {
  int z00 = 1;
  for (int i = 0; i < y00; i++) {
    z00 *= x00;
  }
  return z00;
}
int keta(int x00) {
  int z00 = x00;
  int w00 = 0;
  while (z00 != 0) {
    z00 /= 10;
    w00++;
  }
  return w00;
}
int krag(double xx) { return INF - (int)(INF - xx); }
// x未満の要素数を返す二分探索関数
int b_s(vector<int> &vec, int xx) {
  int t = -1;
  int f = vec.size();
  while (f - t > 1) {
    int m = (t + f) / 2;
    if (vec[m] < xx) { // 未満では<, 以下では<=
      t = m;
    } else {
      f = m;
    }
  }
  return f;
}
template <typename T> void vecout(vector<T> &vec) {
  for (T t : vec)
    cout << t << " ";
  cout << endl;
}
template <typename TT> void vecin(vector<TT> &vec) {
  for (int i = 0; i < vec.size(); i++) {
    cin >> vec[i];
  }
}

// テーブルを作る前処理
void COMinit() {
  fac[0] = fac[1] = 1;
  finv[0] = finv[1] = 1;
  inv[1] = 1;
  for (int i = 2; i < MAX; i++) {
    fac[i] = fac[i - 1] * i % MOD;
    inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
    finv[i] = finv[i - 1] * inv[i] % MOD;
  }
}
// n個を1個以上のx組のグループに分ける重複組み合わせはcom(n-1,x-1)
// グループが0個でもいいときはnにxを足す
//  二項係数計算
long long COM(int n, int k) {
  if (n < k)
    return 0;
  if (n < 0 || k < 0)
    return 0;
  return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD;
}
int modinv(int a, int m) {
  int b = m, u = 1, v = 0;
  while (b) {
    int t = a / b;
    a -= t * b;
    swap(a, b);
    u -= t * v;
    swap(u, v);
  }
  u %= m;
  if (u < 0)
    u += m;
  return u;
}
int modpow(int a, int n) {
  int res = 1;
  while (n > 0) {
    if (n & 1)
      res = res * a % mod;
    a = a * a % mod;
    n >>= 1;
  }
  return res;
}

int gcd(int xx, int yy) {
  int p = xx;
  int q = yy;
  if (q > p)
    swap(p, q);
  while (p % q != 0) {
    p %= q;
    swap(p, q);
  }
  return q;
}
int lcm(int xx, int yy) { return xx * yy / gcd(xx, yy); }
bool prime(int xx) {
  if (xx <= 1) {
    return 0;
  }
  double d = sqrt(xx);
  for (int i = 2; i <= d; i++) {
    if (xx % i == 0) {
      return 0;
    }
  }
  return 1;
}

signed main() {
  int n, d = 1, t = 0;
  cin >> n;
  vector<int> vec(n);
  map<int, int> ma;
  vecin(vec);
  rep(i, n) {
    int j = 2;
    int a = vec[i];
    while (a != 1) {
      if (!prime(j)) {
        j++;
        continue;
      }
      int b = 0;
      while (a % j == 0) {
        a /= j;
        b++;
      }
      ma[j] = max(ma[j], b);
      if (j * j > a) {
        ma[a] = max(1ll, ma[a]);
      }
      j++;
    }
  }
  for (auto p : ma) {
    auto k = p.first;
    auto v = p.second;
    d *= modpow(k, v);
    if (d >= mod)
      d %= mod;
  }
  rep(i, n) { t += (d * modinv(vec[i], mod)) % mod; }
  cout << t % mod << endl;
}


Fixed submission:
#include <algorithm> // min, max, swap, sort, reverse, lower_bound, upper_bound
#include <bitset>    // bitset
#include <cctype>    // isupper, islower, isdigit, toupper, tolower
#include <cmath>
#include <cstdint>  // int64_t, int*_t
#include <cstdio>   // printf
#include <deque>    // deque
#include <iostream> // cout, endl, cin
#include <map>      // map
#include <math.h>
#include <queue> // queue, priority_queue
#include <set>   // set
#include <stack> // stack
#include <stdlib.h>
#include <string>        // string, to_string, stoi
#include <tuple>         // tuple, make_tuple
#include <unordered_map> // unordered_map
#include <unordered_set> // unordered_set
#include <utility>       // pair, make_pair
#include <vector>        // vector

using namespace std;

#define int long long
#define endl "\n"
#define all(v) v.begin(), v.end()
#define fir first
#define sec second
#define m_p make_pair
#define m_t make_tuple
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

const double pai = 3.1415926535897;
const int mod = 1000000007;
const int INF = 2000000015;
const int MAX = 510000;
const int MOD = 1000000007;
long long fac[MAX], finv[MAX], inv[MAX];

int jousu(int x00, int y00) {
  int z00 = 1;
  for (int i = 0; i < y00; i++) {
    z00 *= x00;
  }
  return z00;
}
int keta(int x00) {
  int z00 = x00;
  int w00 = 0;
  while (z00 != 0) {
    z00 /= 10;
    w00++;
  }
  return w00;
}
int krag(double xx) { return INF - (int)(INF - xx); }
// x未満の要素数を返す二分探索関数
int b_s(vector<int> &vec, int xx) {
  int t = -1;
  int f = vec.size();
  while (f - t > 1) {
    int m = (t + f) / 2;
    if (vec[m] < xx) { // 未満では<, 以下では<=
      t = m;
    } else {
      f = m;
    }
  }
  return f;
}
template <typename T> void vecout(vector<T> &vec) {
  for (T t : vec)
    cout << t << " ";
  cout << endl;
}
template <typename TT> void vecin(vector<TT> &vec) {
  for (int i = 0; i < vec.size(); i++) {
    cin >> vec[i];
  }
}

// テーブルを作る前処理
void COMinit() {
  fac[0] = fac[1] = 1;
  finv[0] = finv[1] = 1;
  inv[1] = 1;
  for (int i = 2; i < MAX; i++) {
    fac[i] = fac[i - 1] * i % MOD;
    inv[i] = MOD - inv[MOD % i] * (MOD / i) % MOD;
    finv[i] = finv[i - 1] * inv[i] % MOD;
  }
}
// n個を1個以上のx組のグループに分ける重複組み合わせはcom(n-1,x-1)
// グループが0個でもいいときはnにxを足す
//  二項係数計算
long long COM(int n, int k) {
  if (n < k)
    return 0;
  if (n < 0 || k < 0)
    return 0;
  return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD;
}
int modinv(int a, int m) {
  int b = m, u = 1, v = 0;
  while (b) {
    int t = a / b;
    a -= t * b;
    swap(a, b);
    u -= t * v;
    swap(u, v);
  }
  u %= m;
  if (u < 0)
    u += m;
  return u;
}
int modpow(int a, int n) {
  int res = 1;
  while (n > 0) {
    if (n & 1)
      res = res * a % mod;
    a = a * a % mod;
    n >>= 1;
  }
  return res;
}

int gcd(int xx, int yy) {
  int p = xx;
  int q = yy;
  if (q > p)
    swap(p, q);
  while (p % q != 0) {
    p %= q;
    swap(p, q);
  }
  return q;
}
int lcm(int xx, int yy) { return xx * yy / gcd(xx, yy); }
bool prime(int xx) {
  if (xx <= 1) {
    return 0;
  }
  double d = sqrt(xx);
  for (int i = 2; i <= d; i++) {
    if (xx % i == 0) {
      return 0;
    }
  }
  return 1;
}

signed main() {
  int n, d = 1, t = 0;
  cin >> n;
  vector<int> vec(n);
  map<int, int> ma;
  vecin(vec);
  rep(i, n) {
    int j = 2;
    int a = vec[i];
    while (a != 1) {
      if (!prime(j)) {
        j++;
        continue;
      }
      int b = 0;
      while (a % j == 0) {
        a /= j;
        b++;
      }
      ma[j] = max(ma[j], b);
      if (j * j > a) {
        ma[a] = max(1ll, ma[a]);
        break;
      }
      j++;
    }
  }
  for (auto p : ma) {
    auto k = p.first;
    auto v = p.second;
    d *= modpow(k, v);
    if (d >= mod)
      d %= mod;
  }
  rep(i, n) { t += (d * modinv(vec[i], mod)) % mod; }
  cout << t % mod << endl;
}