Problem p02679 (C++) — buggy submission, verdict: Runtime Error

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

#define ALL(obj) (obj).begin(), (obj).end()
#define SPEED                                                                  \\
  cin.tie(0);                                                                  \\
  ios::sync_with_stdio(false);

template <class T> using PQ = priority_queue<T>;
template <class T> using PQR = priority_queue<T, vector<T>, greater<T>>;

constexpr long long MOD = (long long)1e9 + 7;
constexpr long long MOD2 = 998244353;
constexpr long long HIGHINF = (long long)1e18;
constexpr long long LOWINF = (long long)1e15;
constexpr long double PI = 3.1415926535897932384626433L;

template <class T> vector<T> multivector(size_t N, T init) {
  return vector<T>(N, init);
}
template <class... T> auto multivector(size_t N, T... t) {
  return vector<decltype(multivector(t...))>(N, multivector(t...));
}
template <class T> void corner(bool flg, T hoge) {
  if (flg) {
    cout << hoge << endl;
    exit(0);
  }
}
template <class T, class U>
ostream &operator<<(ostream &o, const map<T, U> &obj) {
  o << "{";
  for (auto &x : obj)
    o << " {" << x.first << " : " << x.second << "}"
      << ",";
  o << " }";
  return o;
}
template <class T> ostream &operator<<(ostream &o, const set<T> &obj) {
  o << "{";
  for (auto itr = obj.begin(); itr != obj.end(); ++itr)
    o << (itr != obj.begin() ? ", " : "") << *itr;
  o << "}";
  return o;
}
template <class T> ostream &operator<<(ostream &o, const multiset<T> &obj) {
  o << "{";
  for (auto itr = obj.begin(); itr != obj.end(); ++itr)
    o << (itr != obj.begin() ? ", " : "") << *itr;
  o << "}";
  return o;
}
template <class T> ostream &operator<<(ostream &o, const vector<T> &obj) {
  o << "{";
  for (int i = 0; i < (int)obj.size(); ++i)
    o << (i > 0 ? ", " : "") << obj[i];
  o << "}";
  return o;
}
template <class T, class U>
ostream &operator<<(ostream &o, const pair<T, U> &obj) {
  o << "{" << obj.first << ", " << obj.second << "}";
  return o;
}
template <template <class tmp> class T, class U>
ostream &operator<<(ostream &o, const T<U> &obj) {
  o << "{";
  for (auto itr = obj.begin(); itr != obj.end(); ++itr)
    o << (itr != obj.begin() ? ", " : "") << *itr;
  o << "}";
  return o;
}
void print(void) { cout << endl; }
template <class Head> void print(Head &&head) {
  cout << head;
  print();
}
template <class Head, class... Tail> void print(Head &&head, Tail &&...tail) {
  cout << head << " ";
  print(forward<Tail>(tail)...);
}
template <class T> void chmax(T &a, const T b) { a = max(a, b); }
template <class T> void chmin(T &a, const T b) { a = min(a, b); }
void YN(bool flg) { cout << (flg ? "YES" : "NO") << endl; }
void Yn(bool flg) { cout << (flg ? "Yes" : "No") << endl; }
void yn(bool flg) { cout << (flg ? "yes" : "no") << endl; }

template <long long mod> class ModInt {
public:
  long long x;
  constexpr ModInt() : x(0) {
    // do nothing
  }
  constexpr ModInt(long long y)
      : x(y >= 0 ? (y % mod) : (mod - (-y) % mod) % mod) {
    // do nothing
  }
  ModInt &operator+=(const ModInt &p) {
    if ((x += p.x) >= mod)
      x -= mod;
    return *this;
  }
  ModInt &operator+=(const long long y) {
    ModInt p(y);
    if ((x += p.x) >= mod)
      x -= mod;
    return *this;
  }
  ModInt &operator+=(const int y) {
    ModInt p(y);
    if ((x += p.x) >= mod)
      x -= mod;
    return *this;
  }
  ModInt &operator-=(const ModInt &p) {
    if ((x += mod - p.x) >= mod)
      x -= mod;
    return *this;
  }
  ModInt &operator-=(const long long y) {
    ModInt p(y);
    if ((x += mod - p.x) >= mod)
      x -= mod;
    return *this;
  }
  ModInt &operator-=(const int y) {
    ModInt p(y);
    if ((x += mod - p.x) >= mod)
      x -= mod;
    return *this;
  }
  ModInt &operator*=(const ModInt &p) {
    x = (x * p.x % mod);
    return *this;
  }
  ModInt &operator*=(const long long y) {
    ModInt p(y);
    x = (x * p.x % mod);
    return *this;
  }
  ModInt &operator*=(const int y) {
    ModInt p(y);
    x = (x * p.x % mod);
    return *this;
  }
  ModInt &operator/=(const ModInt &p) {
    *this *= p.inv();
    return *this;
  }
  ModInt &operator/=(const long long y) {
    ModInt p(y);
    *this *= p.inv();
    return *this;
  }
  ModInt &operator/=(const int y) {
    ModInt p(y);
    *this *= p.inv();
    return *this;
  }
  ModInt operator=(const int y) {
    ModInt p(y);
    *this = p;
    return *this;
  }
  ModInt operator=(const long long y) {
    ModInt p(y);
    *this = p;
    return *this;
  }
  ModInt operator-() const { return ModInt(-x); }
  ModInt operator++() {
    x++;
    if (x >= mod)
      x -= mod;
    return *this;
  }
  ModInt operator--() {
    x--;
    if (x < 0)
      x += mod;
    return *this;
  }
  ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; }
  ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; }
  ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; }
  ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; }
  bool operator==(const ModInt &p) const { return x == p.x; }
  bool operator!=(const ModInt &p) const { return x != p.x; }
  ModInt inv() const {
    int a = x, b = mod, u = 1, v = 0, t;
    while (b > 0) {
      t = a / b;
      swap(a -= t * b, b);
      swap(u -= t * v, v);
    }
    return ModInt(u);
  }
  ModInt pow(long long n) const {
    ModInt ret(1), mul(x);
    while (n > 0) {
      if (n & 1)
        ret *= mul;
      mul *= mul;
      n >>= 1;
    }
    return ret;
  }
  friend ostream &operator<<(ostream &os, const ModInt &p) { return os << p.x; }
  friend istream &operator>>(istream &is, ModInt &a) {
    long long t;
    is >> t;
    a = ModInt<mod>(t);
    return (is);
  }
};
using modint = ModInt<MOD>;

/*
 * @title Gcd
 */
class Gcd {
public:
  inline static long long impl(long long n, long long m) {
    static constexpr long long K = 5;
    long long t, s;
    for (int i = 0; t = n - m, s = n - m * K, i < 80; ++i) {
      if (t < m) {
        if (!t)
          return m;
        n = m, m = t;
      } else {
        if (!m)
          return t;
        n = t;
        if (t >= m * K)
          n = s;
      }
    }
    return impl(m, n % m);
  }
  inline static long long pre(long long n, long long m) {
    long long t;
    for (int i = 0; t = n - m, i < 4; ++i) {
      (t < m ? n = m, m = t : n = t);
      if (!m)
        return n;
    }
    return impl(n, m);
  }
  inline static long long gcd(long long n, long long m) {
    return (n > m ? pre(n, m) : pre(m, n));
  }
  inline static constexpr long long pureGcd(long long a, long long b) {
    return (b ? pureGcd(b, a % b) : a);
  }
  inline static constexpr long long lcm(long long a, long long b) {
    return (a * b ? (a / gcd(a, b) * b) : 0);
  }
  inline static constexpr long long extGcd(long long a, long long b,
                                           long long &x, long long &y) {
    if (b == 0)
      return x = 1, y = 0, a;
    long long d = extGcd(b, a % b, y, x);
    return y -= a / b * x, d;
  }
};

int main() {
  int N;
  cin >> N;
  vector<ll> A(N), B(N);
  map<pair<ll, ll>, int> mp;
  vector<modint> pow2(N + 1, 1);
  for (int i = 1; i <= N; ++i)
    pow2[i] = pow2[i - 1] * 2;
  modint ans2 = 0;
  for (int i = 0; i < N; ++i) {
    cin >> A[i] >> B[i];
    if (A[i] == 0 && B[i] == 0) {
      ans2 += 1;
      continue;
    }
    ll g = Gcd::gcd(abs(A[i]), abs(B[i]));
    A[i] /= g;
    B[i] /= g;
    mp[{A[i], B[i]}] += 1;
  }
  modint ans = 1;
  set<pair<ll, ll>> st;
  st.insert({0, 0});
  for (int i = 0; i < N; ++i) {
    if (st.count({A[i], B[i]}))
      continue;
    int l = mp[{A[i], B[i]}] + mp[{-A[i], -B[i]}];
    int r = mp[{B[i], -A[i]}] + mp[{-B[i], A[i]}];
    st.insert({A[i], B[i]});
    st.insert({-A[i], -B[i]});
    st.insert({B[i], -A[i]});
    st.insert({-B[i], A[i]});
    modint cnt = pow2[l] + pow2[r] - 1;
    ans *= cnt;
  }
  ans -= 1;
  cout << ans + ans2 << endl;

  return 0;
}


Error: 0

Fixed submission:

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

#define ALL(obj) (obj).begin(), (obj).end()
#define SPEED                                                                  \\
  cin.tie(0);                                                                  \\
  ios::sync_with_stdio(false);

template <class T> using PQ = priority_queue<T>;
template <class T> using PQR = priority_queue<T, vector<T>, greater<T>>;

constexpr long long MOD = (long long)1e9 + 7;
constexpr long long MOD2 = 998244353;
constexpr long long HIGHINF = (long long)1e18;
constexpr long long LOWINF = (long long)1e15;
constexpr long double PI = 3.1415926535897932384626433L;

template <class T> vector<T> multivector(size_t N, T init) {
  return vector<T>(N, init);
}
template <class... T> auto multivector(size_t N, T... t) {
  return vector<decltype(multivector(t...))>(N, multivector(t...));
}
template <class T> void corner(bool flg, T hoge) {
  if (flg) {
    cout << hoge << endl;
    exit(0);
  }
}
template <class T, class U>
ostream &operator<<(ostream &o, const map<T, U> &obj) {
  o << "{";
  for (auto &x : obj)
    o << " {" << x.first << " : " << x.second << "}"
      << ",";
  o << " }";
  return o;
}
template <class T> ostream &operator<<(ostream &o, const set<T> &obj) {
  o << "{";
  for (auto itr = obj.begin(); itr != obj.end(); ++itr)
    o << (itr != obj.begin() ? ", " : "") << *itr;
  o << "}";
  return o;
}
template <class T> ostream &operator<<(ostream &o, const multiset<T> &obj) {
  o << "{";
  for (auto itr = obj.begin(); itr != obj.end(); ++itr)
    o << (itr != obj.begin() ? ", " : "") << *itr;
  o << "}";
  return o;
}
template <class T> ostream &operator<<(ostream &o, const vector<T> &obj) {
  o << "{";
  for (int i = 0; i < (int)obj.size(); ++i)
    o << (i > 0 ? ", " : "") << obj[i];
  o << "}";
  return o;
}
template <class T, class U>
ostream &operator<<(ostream &o, const pair<T, U> &obj) {
  o << "{" << obj.first << ", " << obj.second << "}";
  return o;
}
template <template <class tmp> class T, class U>
ostream &operator<<(ostream &o, const T<U> &obj) {
  o << "{";
  for (auto itr = obj.begin(); itr != obj.end(); ++itr)
    o << (itr != obj.begin() ? ", " : "") << *itr;
  o << "}";
  return o;
}
void print(void) { cout << endl; }
template <class Head> void print(Head &&head) {
  cout << head;
  print();
}
template <class Head, class... Tail> void print(Head &&head, Tail &&...tail) {
  cout << head << " ";
  print(forward<Tail>(tail)...);
}
template <class T> void chmax(T &a, const T b) { a = max(a, b); }
template <class T> void chmin(T &a, const T b) { a = min(a, b); }
void YN(bool flg) { cout << (flg ? "YES" : "NO") << endl; }
void Yn(bool flg) { cout << (flg ? "Yes" : "No") << endl; }
void yn(bool flg) { cout << (flg ? "yes" : "no") << endl; }

template <long long mod> class ModInt {
public:
  long long x;
  constexpr ModInt() : x(0) {
    // do nothing
  }
  constexpr ModInt(long long y)
      : x(y >= 0 ? (y % mod) : (mod - (-y) % mod) % mod) {
    // do nothing
  }
  ModInt &operator+=(const ModInt &p) {
    if ((x += p.x) >= mod)
      x -= mod;
    return *this;
  }
  ModInt &operator+=(const long long y) {
    ModInt p(y);
    if ((x += p.x) >= mod)
      x -= mod;
    return *this;
  }
  ModInt &operator+=(const int y) {
    ModInt p(y);
    if ((x += p.x) >= mod)
      x -= mod;
    return *this;
  }
  ModInt &operator-=(const ModInt &p) {
    if ((x += mod - p.x) >= mod)
      x -= mod;
    return *this;
  }
  ModInt &operator-=(const long long y) {
    ModInt p(y);
    if ((x += mod - p.x) >= mod)
      x -= mod;
    return *this;
  }
  ModInt &operator-=(const int y) {
    ModInt p(y);
    if ((x += mod - p.x) >= mod)
      x -= mod;
    return *this;
  }
  ModInt &operator*=(const ModInt &p) {
    x = (x * p.x % mod);
    return *this;
  }
  ModInt &operator*=(const long long y) {
    ModInt p(y);
    x = (x * p.x % mod);
    return *this;
  }
  ModInt &operator*=(const int y) {
    ModInt p(y);
    x = (x * p.x % mod);
    return *this;
  }
  ModInt &operator/=(const ModInt &p) {
    *this *= p.inv();
    return *this;
  }
  ModInt &operator/=(const long long y) {
    ModInt p(y);
    *this *= p.inv();
    return *this;
  }
  ModInt &operator/=(const int y) {
    ModInt p(y);
    *this *= p.inv();
    return *this;
  }
  ModInt operator=(const int y) {
    ModInt p(y);
    *this = p;
    return *this;
  }
  ModInt operator=(const long long y) {
    ModInt p(y);
    *this = p;
    return *this;
  }
  ModInt operator-() const { return ModInt(-x); }
  ModInt operator++() {
    x++;
    if (x >= mod)
      x -= mod;
    return *this;
  }
  ModInt operator--() {
    x--;
    if (x < 0)
      x += mod;
    return *this;
  }
  ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; }
  ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; }
  ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; }
  ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; }
  bool operator==(const ModInt &p) const { return x == p.x; }
  bool operator!=(const ModInt &p) const { return x != p.x; }
  ModInt inv() const {
    int a = x, b = mod, u = 1, v = 0, t;
    while (b > 0) {
      t = a / b;
      swap(a -= t * b, b);
      swap(u -= t * v, v);
    }
    return ModInt(u);
  }
  ModInt pow(long long n) const {
    ModInt ret(1), mul(x);
    while (n > 0) {
      if (n & 1)
        ret *= mul;
      mul *= mul;
      n >>= 1;
    }
    return ret;
  }
  friend ostream &operator<<(ostream &os, const ModInt &p) { return os << p.x; }
  friend istream &operator>>(istream &is, ModInt &a) {
    long long t;
    is >> t;
    a = ModInt<mod>(t);
    return (is);
  }
};
using modint = ModInt<MOD2>;

// Combination Mod
template <long long mod> class CombinationMod {
  vector<long long> fac, finv, inv;

public:
  CombinationMod(int N) : fac(N + 1), finv(N + 1), inv(N + 1) {
    fac[0] = fac[1] = finv[0] = finv[1] = inv[1] = 1;
    for (int i = 2; i <= N; ++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;
    }
  }
  inline long long binom(int n, int k) {
    return ((n < 0 || k < 0 || n < k)
                ? 0
                : fac[n] * (finv[k] * finv[n - k] % mod) % mod);
  }
  inline long long factorial(int n) { return fac[n]; }
  inline static vector<long long> pow2(int n) {
    vector<long long> pow2(n + 1, 1);
    for (int i = 1; i <= n; ++i)
      pow2[i] = (pow2[i - 1] * 2) % mod;
    return pow2;
  }
};

// verify https://atcoder.jp/contests/abc021/tasks/abc021_d

// Pow_Mod O(log(n))
long long PowMod(long long x, long long n, long long mod) {
  long long res = 1;
  for (; n > 0; n >>= 1, (x *= x) %= mod)
    if (n & 1)
      (res *= x) %= mod;
  return res;
}

/*
 * @title Gcd
 */
class Gcd {
public:
  inline static long long impl(long long n, long long m) {
    static constexpr long long K = 5;
    long long t, s;
    for (int i = 0; t = n - m, s = n - m * K, i < 80; ++i) {
      if (t < m) {
        if (!t)
          return m;
        n = m, m = t;
      } else {
        if (!m)
          return t;
        n = t;
        if (t >= m * K)
          n = s;
      }
    }
    return impl(m, n % m);
  }
  inline static long long pre(long long n, long long m) {
    long long t;
    for (int i = 0; t = n - m, i < 4; ++i) {
      (t < m ? n = m, m = t : n = t);
      if (!m)
        return n;
    }
    return impl(n, m);
  }
  inline static long long gcd(long long n, long long m) {
    return (n > m ? pre(n, m) : pre(m, n));
  }
  inline static constexpr long long pureGcd(long long a, long long b) {
    return (b ? pureGcd(b, a % b) : a);
  }
  inline static constexpr long long lcm(long long a, long long b) {
    return (a * b ? (a / gcd(a, b) * b) : 0);
  }
  inline static constexpr long long extGcd(long long a, long long b,
                                           long long &x, long long &y) {
    if (b == 0)
      return x = 1, y = 0, a;
    long long d = extGcd(b, a % b, y, x);
    return y -= a / b * x, d;
  }
};

int main() {
  int N;
  cin >> N;
  vector<ll> A(N), B(N);
  map<pair<ll, ll>, int> mp;
  vector<modint> pow2(N + 1, 1);
  for (int i = 1; i <= N; ++i)
    pow2[i] = pow2[i - 1] * 2;
  for (int i = 0; i < N; ++i) {
    cin >> A[i] >> B[i];
    ll g = Gcd::gcd(abs(A[i]), abs(B[i]));
    A[i] /= g;
    B[i] /= g;
    if (A[i] < 0) {
      A[i] *= -1;
      B[i] *= -1;
    }
    mp[{A[i], B[i]}] += 1;
  }
  modint ans = 1;
  int sum = 0;
  for (auto &e : mp) {
    auto [a, b] = e.first;
    int l = e.second;
    int r = 0;
    mp[{a, b}] = 0;
    if (b < 0) {
      if (mp.count({-b, a})) {
        r = mp[{-b, a}];
        mp[{-b, a}] = 0;
      }
    } else {
      if (mp.count({b, -a})) {
        r = mp[{b, -a}];
        mp[{b, -a}] = 0;
      }
    }
    if (r == 0) {
      sum += l;
      continue;
    }
    modint cnt = pow2[l] + pow2[r] - 1;
    ans *= cnt;
  }
  ans *= pow2[sum];
  ans -= 1;
  cout << ans << endl;

  return 0;
}