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

#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <deque>
#include <fstream>
#include <iostream>
#include <limits>
#include <map>
#include <queue>
#include <random>
#include <regex>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <unordered_map>
#include <utility>
#include <vector>
using namespace std;
typedef long double ld;
typedef long long ll;
typedef vector<int> vint;
typedef vector<ll> vll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<double, double> pdd;
typedef complex<ld> compd;
#define quickIO()                                                              \\
  {                                                                            \\
    cin.tie(0);                                                                \\
    cout.sync_with_stdio(false);                                               \\
  }
#define reach(i, a) for (auto i : a)
#define rep(i, n) for (int i = 0; i < ((int)n); i++)
#define REP(i, n) for (int i = 0; i <= ((int)n); i++)
#define srep(i, a, n) for (int i = a; i < ((int)n); i++)
#define SREP(i, a, n) for (int i = a; i <= ((int)n); i++)
#define rrep(i, n) for (int i = n - 1; i >= 0; i--)
#define RREP(i, n) for (int i = n; i >= 0; i--)
#define all(a) (a).begin(), (a).end()
#define mp(a, b) make_pair(a, b)
#define mt make_tuple
#define pb push_back
template <typename T> istream &operator>>(istream &is, vector<T> &vec) {
  for (T &x : vec)
    is >> x;
  return is;
}
template <typename T> ostream &operator<<(ostream &os, vector<T> &vec) {
  os << "[";
  rep(i, vec.size()) os << (i ? ", " : "") << vec[i];
  os << "]";
  return os;
}
template <typename T> istream &operator>>(istream &is, pair<T, T> &p) {
  is >> p.first >> p.second;
  return is;
}
template <typename T> ostream &operator<<(ostream &os, pair<T, T> &p) {
  os << p.first << " " << p.second;
  return os;
}
template <typename T> bool operator<(vector<T> &a, vector<T> &b) {
  rep(i, a.size()) {
    if (i == b.size())
      return false;
    if (a[i] < b[i])
      return true;
    else if (a[i] > b[i])
      return false;
  }
  return false;
}
template <typename T> bool operator>(vector<T> &a, vector<T> &b) {
  rep(i, a.size()) {
    if (i == b.size())
      return true;
    if (a[i] < b[i])
      return false;
    else if (a[i] > b[i])
      return true;
  }
  return false;
}
int bitcnt(ll x) {
  x = ((x & 0xAAAAAAAAAAAAAAAA) >> 1) + (x & 0x5555555555555555);
  x = ((x & 0xCCCCCCCCCCCCCCCC) >> 2) + (x & 0x3333333333333333);
  x = ((x & 0xF0F0F0F0F0F0F0F0) >> 4) + (x & 0x0F0F0F0F0F0F0F0F);
  x = ((x & 0xFF00FF00FF00FF00) >> 8) + (x & 0x00FF00FF00FF00FF);
  x = ((x & 0xFFFF0000FFFF0000) >> 16) + (x & 0x0000FFFF0000FFFF);
  x = ((x & 0xFFFFFFFF00000000) >> 32) + (x & 0x00000000FFFFFFFF);
  return x;
}
int bitcnt(int x) {
  x = ((x & 0xAAAAAAAA) >> 1) + (x & 0x55555555);
  x = ((x & 0xCCCCCCCC) >> 2) + (x & 0x33333333);
  x = ((x & 0xF0F0F0F0) >> 4) + (x & 0x0F0F0F0F);
  x = ((x & 0xFF00FF00) >> 8) + (x & 0x00FF00FF);
  x = ((x & 0xFFFF0000) >> 16) + (x & 0x0000FFFF);
  return x;
}
ll sqrtll(ll x) {
  ll left = 0, right = x;
  rep(i, 100) {
    ll mid = (left + right) >> 1;
    if (mid * mid <= x)
      left = mid;
    else
      right = mid;
  }
  return left;
}
ll gcd(ll a, ll b) { return b == 0 ? a : gcd(b, a % b); }
#define debug(x) printf("Case #%d: ", x)
#define DEBUG 0
const ld infl = 1e100;
const ll mod = 1e9 + 7;
const ld eps = 1e-9;
const ll inf = 1e15;
const int dx[] = {1, 0, -1, 0, 0};
const int dy[] = {0, 1, 0, -1, 0};

ll pow2[200010];

int main() {
  int n;
  cin >> n;
  pow2[0] = 1;
  SREP(i, 1, n) { pow2[i] = (pow2[i - 1] * 2) % mod; }
  vector<pll> d;
  multiset<pll> ms;
  ll zero = 0;
  rep(i, n) {
    ll a, b;
    cin >> a >> b;
    if (a == 0 && b == 0) {
      zero++;
      continue;
    }
    if (a == 0)
      b /= llabs(b);
    else if (b == 0)
      a /= llabs(a);
    else {
      ll g = gcd(llabs(a), llabs(b));
      a /= g;
      b /= g;
    }
    if (b < 0 || (b == 0 && a < 0)) {
      a = -a;
      b = -b;
    }
    ms.insert(mp(a, b));
    d.push_back(mp(a, b));
  }
  ll res = 1;
  for (auto it : d) {
    if (!ms.count(it))
      continue;
    ll a = it.first, b = it.second;
    ll ta = -b, tb = a;
    if (tb < 0 || (tb == 0 && ta < 0)) {
      ta = -ta;
      tb = -tb;
    }
    ll cnt1 = ms.count(mp(a, b));
    ll cnt2 = ms.count(mp(ta, tb));
    ll mul = ((pow2[cnt1] - 1) + (pow2[cnt2] - 1) + 1) % mod;
    res = (res * mul) % mod;
    ms.erase(mp(a, b));
    ms.erase(mp(ta, tb));
  }
  cout << (res + zero + mod - 1) % mod << endl;
  return 0;
}

Error: 0

Fixed submission:

#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <deque>
#include <fstream>
#include <iostream>
#include <limits>
#include <map>
#include <queue>
#include <random>
#include <regex>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <unordered_map>
#include <utility>
#include <vector>
using namespace std;
typedef long double ld;
typedef long long ll;
typedef vector<int> vint;
typedef vector<ll> vll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<double, double> pdd;
typedef complex<ld> compd;
#define quickIO()                                                              \\
  {                                                                            \\
    cin.tie(0);                                                                \\
    cout.sync_with_stdio(false);                                               \\
  }
#define reach(i, a) for (auto i : a)
#define rep(i, n) for (int i = 0; i < ((int)n); i++)
#define REP(i, n) for (int i = 0; i <= ((int)n); i++)
#define srep(i, a, n) for (int i = a; i < ((int)n); i++)
#define SREP(i, a, n) for (int i = a; i <= ((int)n); i++)
#define rrep(i, n) for (int i = n - 1; i >= 0; i--)
#define RREP(i, n) for (int i = n; i >= 0; i--)
#define all(a) (a).begin(), (a).end()
#define mp(a, b) make_pair(a, b)
#define mt make_tuple
#define pb push_back
template <typename T> istream &operator>>(istream &is, vector<T> &vec) {
  for (T &x : vec)
    is >> x;
  return is;
}
template <typename T> ostream &operator<<(ostream &os, vector<T> &vec) {
  os << "[";
  rep(i, vec.size()) os << (i ? ", " : "") << vec[i];
  os << "]";
  return os;
}
template <typename T> istream &operator>>(istream &is, pair<T, T> &p) {
  is >> p.first >> p.second;
  return is;
}
template <typename T> ostream &operator<<(ostream &os, pair<T, T> &p) {
  os << p.first << " " << p.second;
  return os;
}
template <typename T> bool operator<(vector<T> &a, vector<T> &b) {
  rep(i, a.size()) {
    if (i == b.size())
      return false;
    if (a[i] < b[i])
      return true;
    else if (a[i] > b[i])
      return false;
  }
  return false;
}
template <typename T> bool operator>(vector<T> &a, vector<T> &b) {
  rep(i, a.size()) {
    if (i == b.size())
      return true;
    if (a[i] < b[i])
      return false;
    else if (a[i] > b[i])
      return true;
  }
  return false;
}
int bitcnt(ll x) {
  x = ((x & 0xAAAAAAAAAAAAAAAA) >> 1) + (x & 0x5555555555555555);
  x = ((x & 0xCCCCCCCCCCCCCCCC) >> 2) + (x & 0x3333333333333333);
  x = ((x & 0xF0F0F0F0F0F0F0F0) >> 4) + (x & 0x0F0F0F0F0F0F0F0F);
  x = ((x & 0xFF00FF00FF00FF00) >> 8) + (x & 0x00FF00FF00FF00FF);
  x = ((x & 0xFFFF0000FFFF0000) >> 16) + (x & 0x0000FFFF0000FFFF);
  x = ((x & 0xFFFFFFFF00000000) >> 32) + (x & 0x00000000FFFFFFFF);
  return x;
}
int bitcnt(int x) {
  x = ((x & 0xAAAAAAAA) >> 1) + (x & 0x55555555);
  x = ((x & 0xCCCCCCCC) >> 2) + (x & 0x33333333);
  x = ((x & 0xF0F0F0F0) >> 4) + (x & 0x0F0F0F0F);
  x = ((x & 0xFF00FF00) >> 8) + (x & 0x00FF00FF);
  x = ((x & 0xFFFF0000) >> 16) + (x & 0x0000FFFF);
  return x;
}
ll sqrtll(ll x) {
  ll left = 0, right = x;
  rep(i, 100) {
    ll mid = (left + right) >> 1;
    if (mid * mid <= x)
      left = mid;
    else
      right = mid;
  }
  return left;
}
ll gcd(ll a, ll b) { return b == 0 ? a : gcd(b, a % b); }
#define debug(x) printf("Case #%d: ", x)
#define DEBUG 0
const ld infl = 1e100;
const ll mod = 1e9 + 7;
const ld eps = 1e-9;
const ll inf = 1e15;
const int dx[] = {1, 0, -1, 0, 0};
const int dy[] = {0, 1, 0, -1, 0};

ll pow2[2000010];

int main() {
  int n;
  cin >> n;
  pow2[0] = 1;
  SREP(i, 1, n) { pow2[i] = (pow2[i - 1] * 2) % mod; }
  vector<pll> d;
  multiset<pll> m;
  rep(i, n) {
    ll a, b;
    cin >> a >> b;
    ll g = gcd(a, b);
    a /= g;
    b /= g;
    d.push_back(mp(a, b));
    m.insert(mp(a, b));
  }
  ll res = 1;
  for (auto it : d) {
    if (!m.count(it))
      continue;
    ll a = it.first, b = it.second;
    ll cnt1 = (ll)m.count(it) + m.count(mp(-a, -b));
    ll cnt2 = (ll)m.count(mp(-b, a)) + m.count(mp(b, -a));
    ll mul = (pow2[cnt1] + pow2[cnt2] - 1) % mod;
    res = (res * mul) % mod;
    m.erase(it);
    m.erase(mp(-a, -b));
    m.erase(mp(-b, a));
    m.erase(mp(b, -a));
  }
  cout << (res + mod - 1) % mod << endl;
  return 0;
}