Problem p02658 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <bits/stdc++.h>
using namespace std;

// conversion
//------------------------------------------
inline int toInt(string s) {
  int v;
  istringstream sin(s);
  sin >> v;
  return v;
}
template <class T> inline string toString(T x) {
  ostringstream sout;
  sout << x;
  return sout.str();
}

// math
//-------------------------------------------
template <class T> inline T sqr(T x) { return x * x; }

// typedef
//------------------------------------------
typedef long long LL;
typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<LL> VLL;
typedef vector<VLL> VVLL;
typedef vector<bool> VB;
typedef vector<VB> VVB;
typedef vector<double> VD;
typedef vector<VD> VVD;
typedef vector<string> VS;
typedef vector<VS> VVS;
typedef vector<char> VC;
typedef vector<VC> VVC;
typedef vector<PII> VPII;
typedef vector<PLL> VPLL;
typedef priority_queue<int> PQGI; // 大きい順
typedef priority_queue<int, VI, greater<int>> PQLI;
typedef priority_queue<PII> PQGP;
typedef priority_queue<PII, VPII, greater<int>> PQLP;

// container util
//------------------------------------------
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define EB emplace_back
#define PB push_back
#define PF push_front
#define POB pop_back
#define POF pop_front
#define MP make_pair
#define SZ(a) int((a).size())
#define SQ(a) ((a) * (a))
#define EACH(i, c)                                                             \\
  for (typeof((c).begin()) i = (c).begin(); i != (c).end(); ++i)
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c) sort((c).begin(), (c).end())
#define SORTR(c) sort((c).rbegin(), (c).rend())
#define LB lower_bound
#define UB upper_bound
#define NEXP next_permutation
#define FI first
#define SE second
#define Vmin(a) *min_element((a).begin(), (a).end())
#define Vmax(a) *max_element((a).begin(), (a).end())

// repetition
//------------------------------------------
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define REP(i, n) FOR(i, 0, n)
#define FORR(i, a, b) for (int i = (b - 1); i >= (a); i--)
#define REPR(i, n) FORR(i, 0, n)
#define CFOR(i, a, b) for (int i = (a); i <= (b); ++i)
#define CREP(i, n) CFOR(i, 0, n)
#define CFORR(i, a, b) for (int i = (b); i >= (a); i--)
#define CREPR(i, n) CFORR(i, 0, n)
#define BFOR(bit, a, b) for (int bit = (a); bit < (1 << (b)); ++bit)
#define BREP(bit, n) BFOR(bit, 0, n)

// constant
//--------------------------------------------
const double EPS = 1e-10;
const double PI = acos(-1.0);
const int INF = INT_MAX / 2;
const LL LINF = LLONG_MAX / 3;
const int RINF = INT_MIN / 2;
const LL RLINF = LLONG_MIN / 3;
const LL MOD = 1e9 + 7;
const LL MODD = 998244353;
const int MAX = 510000;

inline bool Eq(double a, double b) { return fabs(b - a) < EPS; }

// other
//-------------------------------------------
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}

#define COUT(x) cout << (x) << endl
#define COUT2(x, y) cout << (x) << " " << (y) << endl
#define COUT3(x, y, z) cout << (x) << " " << (y) << " " << (z) << endl
#define PR(x) cout << (x)
#define ENDL cout << endl
#define SPACE cout << " "
#define BC(x) __builtin_popcountll(x)

VI dx = {1, 0, -1, 0, 1, 1, -1, -1};
VI dy = {0, 1, 0, -1, 1, -1, 1, -1};

LL Gcd(LL a, LL b) { return __gcd(a, b); }
LL Lcm(LL a, LL b) { return a / Gcd(a, b) * b; }

LL ModPow(LL A, LL N, LL M) {
  LL res = 1;
  while (N > 0) {
    if (N & 1)
      res = res * A % M;
    A = A * A % M;
    N >>= 1;
  }
  return res;
}

template <typename T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p) {
  is >> p.first >> p.second;
  return is;
}

template <typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
  os << p.first << " " << p.second;
  return os;
}

template <typename T> istream &operator>>(istream &is, vector<T> &v) {
  for (T &in : v)
    is >> in;
  return is;
}

template <typename T> ostream &operator<<(ostream &os, const vector<T> &v) {
  for (int i = 0; i < (int)v.size(); i++) {
    os << v[i] << (i + 1 != v.size() ? " " : "");
  }
  return os;
}

template <typename T> vector<T> make_v(size_t a, T b) {
  return vector<T>(a, b);
}
template <typename... Ts> auto make_v(size_t a, Ts... ts) {
  return vector<decltype(make_v(ts...))>(a, make_v(ts...));
}

namespace BigInt {
using bigint = vector<int>;
bigint strtobigint(string S) {
  int N = SZ(S);
  bigint digit(N);
  REP(i, N) { digit.at(i) = S.at(N - i - 1) - '0'; }
  while (SZ(digit) > 1 && digit.back() == 0)
    digit.pop_back();
  return digit;
}
string biginttostr(bigint digit) {
  int N = SZ(digit);
  string str(N, '0');
  REP(i, N) { str.at(i) += digit.at(N - i - 1); }
  return str;
}
bigint carrt_ans_fix(bigint digit) {
  int N = SZ(digit);
  REP(i, N - 1) {
    if (digit.at(i) >= 10) {
      int K = digit.at(i) / 10;
      digit.at(i) %= 10;
      digit.at(i + 1) += K;
    }
    if (digit.at(i) < 0) {
      int K = (-digit.at(i) - 1) / 10 + 1;
      digit.at(i) += K * 10;
      digit.at(i + 1) -= K;
    }
  }
  while (digit.back() >= 10) {
    int K = digit.back() / 10;
    digit.back() %= 10;
    digit.PB(K);
  }
  while (SZ(digit) > 1 && digit.back() == 0)
    digit.pop_back();
  return digit;
}
bigint addtion(bigint a, bigint b) {
  int N = max(SZ(a), SZ(b));
  bigint res(N);
  REP(i, N) {
    res.at(i) = (i < SZ(a) ? a.at(i) : 0) + (i < SZ(b) ? b.at(i) : 0);
  }
  return carrt_ans_fix(res);
}
bigint substraction(bigint a, bigint b) {
  int N = max(SZ(a), SZ(b));
  bigint res(N);
  REP(i, N) {
    res.at(i) = (i < SZ(a) ? a.at(i) : 0) - (i < SZ(b) ? b.at(i) : 0);
  }
  return carrt_ans_fix(res);
}
bigint multiplication(bigint a, bigint b) {
  int Na = SZ(a), Nb = SZ(b);
  bigint res(Na + Nb - 1, 0);
  REP(i, Na) REP(j, Nb) { res.at(i + j) += a.at(i) * b.at(j); }
  return carrt_ans_fix(res);
}
int compare_bigint(bigint a, bigint b) {
  int Na = SZ(a), Nb = SZ(b);
  if (Na > Nb)
    return 1;
  if (Na < Nb)
    return -1;
  REPR(i, Na) {
    if (a.at(i) > b.at(i))
      return 1;
    if (a.at(i) < b.at(i))
      return -1;
  }
  return 0;
}
} // namespace BigInt

int main() {

  // cin.tie(0);
  // ios::sync_with_stdio(false);
  cout << fixed << setprecision(12);

  int N;
  cin >> N;

  BigInt::bigint limit = BigInt::strtobigint("1000000000000000000");

  BigInt::bigint sum = BigInt::strtobigint("1");
  VLL A(N);
  cin >> A;
  SORT(A);
  if (A.at(0) == 0) {
    COUT(0);
    return 0;
  }

  REP(i, N) {
    string B = toString(A.at(i));
    BigInt::bigint C = BigInt::strtobigint(B);
    sum = BigInt::multiplication(sum, C);
    if (BigInt::compare_bigint(sum, limit) == 1) {
      COUT(-1);
      return 0;
    }
  }

  if (BigInt::compare_bigint(sum, limit) == 1) {
    COUT(-1);
  } else {
    string ans = BigInt::biginttostr(sum);
    COUT(ans);
  }

  return 0;
}


Error: TLE

Fixed submission:

#include <bits/stdc++.h>
using namespace std;

// conversion
//------------------------------------------
inline int toInt(string s) {
  int v;
  istringstream sin(s);
  sin >> v;
  return v;
}
template <class T> inline string toString(T x) {
  ostringstream sout;
  sout << x;
  return sout.str();
}

// math
//-------------------------------------------
template <class T> inline T sqr(T x) { return x * x; }

// typedef
//------------------------------------------
typedef long long LL;
typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<LL> VLL;
typedef vector<VLL> VVLL;
typedef vector<bool> VB;
typedef vector<VB> VVB;
typedef vector<double> VD;
typedef vector<VD> VVD;
typedef vector<string> VS;
typedef vector<VS> VVS;
typedef vector<char> VC;
typedef vector<VC> VVC;
typedef vector<PII> VPII;
typedef vector<PLL> VPLL;
typedef priority_queue<int> PQGI; // 大きい順
typedef priority_queue<int, VI, greater<int>> PQLI;
typedef priority_queue<PII> PQGP;
typedef priority_queue<PII, VPII, greater<int>> PQLP;

// container util
//------------------------------------------
#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define EB emplace_back
#define PB push_back
#define PF push_front
#define POB pop_back
#define POF pop_front
#define MP make_pair
#define SZ(a) int((a).size())
#define SQ(a) ((a) * (a))
#define EACH(i, c)                                                             \\
  for (typeof((c).begin()) i = (c).begin(); i != (c).end(); ++i)
#define EXIST(s, e) ((s).find(e) != (s).end())
#define SORT(c) sort((c).begin(), (c).end())
#define SORTR(c) sort((c).rbegin(), (c).rend())
#define LB lower_bound
#define UB upper_bound
#define NEXP next_permutation
#define FI first
#define SE second
#define Vmin(a) *min_element((a).begin(), (a).end())
#define Vmax(a) *max_element((a).begin(), (a).end())

// repetition
//------------------------------------------
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define REP(i, n) FOR(i, 0, n)
#define FORR(i, a, b) for (int i = (b - 1); i >= (a); i--)
#define REPR(i, n) FORR(i, 0, n)
#define CFOR(i, a, b) for (int i = (a); i <= (b); ++i)
#define CREP(i, n) CFOR(i, 0, n)
#define CFORR(i, a, b) for (int i = (b); i >= (a); i--)
#define CREPR(i, n) CFORR(i, 0, n)
#define BFOR(bit, a, b) for (int bit = (a); bit < (1 << (b)); ++bit)
#define BREP(bit, n) BFOR(bit, 0, n)

// constant
//--------------------------------------------
const double EPS = 1e-10;
const double PI = acos(-1.0);
const int INF = INT_MAX / 2;
const LL LINF = LLONG_MAX / 3;
const int RINF = INT_MIN / 2;
const LL RLINF = LLONG_MIN / 3;
const LL MOD = 1e9 + 7;
const LL MODD = 998244353;
const int MAX = 510000;

inline bool Eq(double a, double b) { return fabs(b - a) < EPS; }

// other
//-------------------------------------------
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}

#define COUT(x) cout << (x) << endl
#define COUT2(x, y) cout << (x) << " " << (y) << endl
#define COUT3(x, y, z) cout << (x) << " " << (y) << " " << (z) << endl
#define PR(x) cout << (x)
#define ENDL cout << endl
#define SPACE cout << " "
#define BC(x) __builtin_popcountll(x)

VI dx = {1, 0, -1, 0, 1, 1, -1, -1};
VI dy = {0, 1, 0, -1, 1, -1, 1, -1};

LL Gcd(LL a, LL b) { return __gcd(a, b); }
LL Lcm(LL a, LL b) { return a / Gcd(a, b) * b; }

LL ModPow(LL A, LL N, LL M) {
  LL res = 1;
  while (N > 0) {
    if (N & 1)
      res = res * A % M;
    A = A * A % M;
    N >>= 1;
  }
  return res;
}

template <typename T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p) {
  is >> p.first >> p.second;
  return is;
}

template <typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
  os << p.first << " " << p.second;
  return os;
}

template <typename T> istream &operator>>(istream &is, vector<T> &v) {
  for (T &in : v)
    is >> in;
  return is;
}

template <typename T> ostream &operator<<(ostream &os, const vector<T> &v) {
  for (int i = 0; i < (int)v.size(); i++) {
    os << v[i] << (i + 1 != v.size() ? " " : "");
  }
  return os;
}

template <typename T> vector<T> make_v(size_t a, T b) {
  return vector<T>(a, b);
}
template <typename... Ts> auto make_v(size_t a, Ts... ts) {
  return vector<decltype(make_v(ts...))>(a, make_v(ts...));
}

namespace BigInt {
using bigint = vector<int>;
bigint strtobigint(string S) {
  int N = SZ(S);
  bigint digit(N);
  REP(i, N) { digit.at(i) = S.at(N - i - 1) - '0'; }
  while (SZ(digit) > 1 && digit.back() == 0)
    digit.pop_back();
  return digit;
}
string biginttostr(bigint digit) {
  int N = SZ(digit);
  string str(N, '0');
  REP(i, N) { str.at(i) += digit.at(N - i - 1); }
  return str;
}
bigint carrt_ans_fix(bigint digit) {
  int N = SZ(digit);
  REP(i, N - 1) {
    if (digit.at(i) >= 10) {
      int K = digit.at(i) / 10;
      digit.at(i) %= 10;
      digit.at(i + 1) += K;
    }
    if (digit.at(i) < 0) {
      int K = (-digit.at(i) - 1) / 10 + 1;
      digit.at(i) += K * 10;
      digit.at(i + 1) -= K;
    }
  }
  while (digit.back() >= 10) {
    int K = digit.back() / 10;
    digit.back() %= 10;
    digit.PB(K);
  }
  while (SZ(digit) > 1 && digit.back() == 0)
    digit.pop_back();
  return digit;
}
bigint addtion(bigint a, bigint b) {
  int N = max(SZ(a), SZ(b));
  bigint res(N);
  REP(i, N) {
    res.at(i) = (i < SZ(a) ? a.at(i) : 0) + (i < SZ(b) ? b.at(i) : 0);
  }
  return carrt_ans_fix(res);
}
bigint substraction(bigint a, bigint b) {
  int N = max(SZ(a), SZ(b));
  bigint res(N);
  REP(i, N) {
    res.at(i) = (i < SZ(a) ? a.at(i) : 0) - (i < SZ(b) ? b.at(i) : 0);
  }
  return carrt_ans_fix(res);
}
bigint multiplication(bigint a, bigint b) {
  int Na = SZ(a), Nb = SZ(b);
  bigint res(Na + Nb - 1, 0);
  REP(i, Na) REP(j, Nb) { res.at(i + j) += a.at(i) * b.at(j); }
  return carrt_ans_fix(res);
}
int compare_bigint(bigint a, bigint b) {
  int Na = SZ(a), Nb = SZ(b);
  if (Na > Nb)
    return 1;
  if (Na < Nb)
    return -1;
  REPR(i, Na) {
    if (a.at(i) > b.at(i))
      return 1;
    if (a.at(i) < b.at(i))
      return -1;
  }
  return 0;
}
} // namespace BigInt

int main() {

  // cin.tie(0);
  // ios::sync_with_stdio(false);
  cout << fixed << setprecision(12);

  int N;
  cin >> N;

  BigInt::bigint limit = BigInt::strtobigint("1000000000000000000");

  BigInt::bigint sum = BigInt::strtobigint("1");

  REP(i, N) {
    string A;
    cin >> A;
    BigInt::bigint B = BigInt::strtobigint(A);
    sum = BigInt::multiplication(sum, B);
  }

  if (BigInt::compare_bigint(sum, limit) == 1) {
    COUT(-1);
  } else {
    string ans = BigInt::biginttostr(sum);
    COUT(ans);
  }

  return 0;
}