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

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#define INF (1LL << 59)
#define MV 200001
#define LMV 21
#define ff first
#define ss second
#define pb push_back
#define eb emplace_back
#define emp emplace
#define whoami(x) cerr << #x << " " << x << "\\n";
#define mp make_pair
#define ins insert
#define sz size

void FLASH() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
}
void SETF() {
  cout.ios_base::setf(ios_base::fixed);
  cerr.ios_base::setf(ios_base::fixed);
}
void UNSETF() {
  cout.ios_base::unsetf(ios_base::fixed);
  cerr.ios_base::unsetf(ios_base::fixed);
}

typedef long long ll;
typedef long double ld;
typedef vector<int> VI;
typedef vector<ll> VL;
typedef pair<int, int> PII;
typedef pair<ll, ll> PLL;
typedef pair<PII, int> PPII;
typedef pair<PLL, ll> PPLL;
typedef map<int, int> MII;

const int MOD = 1000000007;

template <typename T>
using ordered_set =
    tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template <typename T>
using ordered_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag,
                              tree_order_statistics_node_update>;

struct h_llint {
  static uint64_t
  splitmix64(uint64_t x) { // http://xorshift.di.unimi.it/splitmix64.c
    x += 0x9e3779b97f4a7c15;
    x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
    x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
    return x ^ (x >> 31);
  }
  size_t operator()(uint64_t x) const {
    static const uint64_t FIXED_RANDOM =
        chrono::steady_clock::now().time_since_epoch().count();
    return splitmix64(x + FIXED_RANDOM);
  }
};

struct h_pair {
  size_t operator()(const PLL &x) const {
    return hash<ll>()(((ll)x.ff) ^ (((ll)x.ss) << 32));
  }
};

typedef map<ll, ll> MLL;
typedef map<PII, int> MPII;
typedef map<PLL, ll> MPLL;
typedef set<int> SI;
typedef set<ll> SL;
// ordered_set = order_of_key(.)
// ordered_set = find_by_order(.)
typedef ordered_set<int> OSI;
typedef ordered_set<ll> OSL;
typedef ordered_multiset<int> MOSI;
typedef ordered_multiset<ll> MOSL;
typedef unordered_map<ll, int, h_llint> UMLI;
typedef unordered_map<ll, ll, h_llint> UMLL;
typedef unordered_map<PLL, int, h_pair> UMPI;
typedef unordered_map<PLL, ll, h_pair> UMPL;

int ar[MV];
ll arr[MV];
map<PLL, ll> dd1;
map<PLL, bool> vis;

ll modexp(ll a, ll n) {
  ll res = 1;
  while (n) {
    if (n & 1)
      res = ((res % MOD) * (a % MOD)) % MOD;
    a = ((a % MOD) * (a % MOD)) % MOD;
    n >>= 1;
  }
  return res;
}

void solve(int T) {
  int n;
  cin >> n;
  vector<PLL> axd(n);
  for (auto &&u : axd) {
    cin >> u.ff >> u.ss;
    int sg1 = 0, sg2 = 0;
    if (u.ff < 0)
      sg1 = 1;
    if (u.ss < 0)
      sg2 = 1;
    if (sg1 && sg2) {
      u.ff = -u.ff;
      u.ss = -u.ss;
    }
    if (sg1 && !sg2) {
      u.ff = -u.ff;
      u.ss = -u.ss;
    }
    if ((u.ff == 0) || (u.ss == 0)) {
      u.ff = abs(u.ff);
      u.ss = abs(u.ss);
    }
    ll gc = __gcd(abs(u.ff), abs(u.ss));
    if (gc > 0) {
      u.ff /= gc;
      u.ss /= gc;
    }
    dd1[u]++;
  }
  ll fc = 1;
  for (auto &&u : dd1) {
    if (((u.ff.ff != 0) || (u.ff.ss != 0)) && !vis[u.ff]) {
      vis[u.ff] = 1;
      ll ax = abs(u.ff.ss);
      ll bx = abs(u.ff.ff);
      if (u.ff.ss >= 0)
        bx = -bx;
      if (dd1.count({ax, bx})) {
        vis[{ax, bx}] = 1;
        fc = ((fc % MOD) *
              (((((modexp(2, u.ss) % MOD) + (modexp(2, dd1[{ax, bx}]) % MOD)) %
                 MOD) -
                1 + MOD) %
               MOD)) %
             MOD;
      } else
        fc = ((fc % MOD) * (modexp(2, u.ss) % MOD)) % MOD;
    }
  }
  fc = ((fc % MOD) - 1 + MOD) % MOD;
  if (dd1.count({0, 0}))
    fc = ((fc % MOD) + (dd1[{0, 0}] % MOD)) % MOD;
  cout << fc << "\\n";
  return;
}

int main(void) {
  FLASH();
  // freopen("cowjog.in", "r", stdin);
  // freopen("cowjog.out", "w", stdout);
  int T;
  T = 1;

#ifndef ONLINE_JUDGE
  time_t time_t1, time_t2;
  time_t1 = clock();
#endif

  // cin>>T;
  while (T--)
    solve(T);

#ifndef ONLINE_JUDGE
  time_t2 = clock();
  SETF();
  cerr << "Time taken: " << setprecision(7)
       << (time_t2 - time_t1) / (double)CLOCKS_PER_SEC << "\\n";
  UNSETF();
#endif

  return 0;
}

Error: 0
Time taken: 0.0000730


Fixed submission:

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#define INF (1LL << 59)
#define MV 200001
#define LMV 21
#define ff first
#define ss second
#define pb push_back
#define eb emplace_back
#define emp emplace
#define whoami(x) cerr << #x << " " << x << "\\n";
#define mp make_pair
#define ins insert
#define sz size

void FLASH() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
}
void SETF() {
  cout.ios_base::setf(ios_base::fixed);
  cerr.ios_base::setf(ios_base::fixed);
}
void UNSETF() {
  cout.ios_base::unsetf(ios_base::fixed);
  cerr.ios_base::unsetf(ios_base::fixed);
}

typedef long long ll;
typedef long double ld;
typedef vector<int> VI;
typedef vector<ll> VL;
typedef pair<int, int> PII;
typedef pair<ll, ll> PLL;
typedef pair<PII, int> PPII;
typedef pair<PLL, ll> PPLL;
typedef map<int, int> MII;

const int MOD = 1000000007;

template <typename T>
using ordered_set =
    tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template <typename T>
using ordered_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag,
                              tree_order_statistics_node_update>;

struct h_llint {
  static uint64_t
  splitmix64(uint64_t x) { // http://xorshift.di.unimi.it/splitmix64.c
    x += 0x9e3779b97f4a7c15;
    x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
    x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
    return x ^ (x >> 31);
  }
  size_t operator()(uint64_t x) const {
    static const uint64_t FIXED_RANDOM =
        chrono::steady_clock::now().time_since_epoch().count();
    return splitmix64(x + FIXED_RANDOM);
  }
};

struct h_pair {
  size_t operator()(const PLL &x) const {
    return hash<ll>()(((ll)x.ff) ^ (((ll)x.ss) << 32));
  }
};

typedef map<ll, ll> MLL;
typedef map<PII, int> MPII;
typedef map<PLL, ll> MPLL;
typedef set<int> SI;
typedef set<ll> SL;
// ordered_set = order_of_key(.)
// ordered_set = find_by_order(.)
typedef ordered_set<int> OSI;
typedef ordered_set<ll> OSL;
typedef ordered_multiset<int> MOSI;
typedef ordered_multiset<ll> MOSL;
typedef unordered_map<ll, int, h_llint> UMLI;
typedef unordered_map<ll, ll, h_llint> UMLL;
typedef unordered_map<PLL, int, h_pair> UMPI;
typedef unordered_map<PLL, ll, h_pair> UMPL;

int ar[MV];
ll arr[MV];
map<PLL, ll> dd1;
map<PLL, bool> vis;

ll modexp(ll a, ll n) {
  ll res = 1;
  while (n) {
    if (n & 1)
      res = ((res % MOD) * (a % MOD)) % MOD;
    a = ((a % MOD) * (a % MOD)) % MOD;
    n >>= 1;
  }
  return res;
}

void solve(int T) {
  int n;
  cin >> n;
  vector<PLL> axd(n);
  for (auto &&u : axd) {
    cin >> u.ff >> u.ss;
    int sg1 = 0, sg2 = 0;
    if (u.ff < 0)
      sg1 = 1;
    if (u.ss < 0)
      sg2 = 1;
    if (sg1 && sg2) {
      u.ff = -u.ff;
      u.ss = -u.ss;
    }
    if (sg1 && !sg2) {
      u.ff = -u.ff;
      u.ss = -u.ss;
    }
    ll gc = __gcd(abs(u.ff), abs(u.ss));
    u.ff /= gc;
    u.ss /= gc;
    dd1[u]++;
  }
  ll fc = 1;
  for (auto &&u : dd1) {
    if (!vis[u.ff]) {
      vis[u.ff] = 1;
      ll ax = abs(u.ff.ss);
      ll bx = abs(u.ff.ff);
      if (u.ff.ss >= 0)
        bx = -bx;
      if (dd1.count({ax, bx})) {
        vis[{ax, bx}] = 1;
        fc = ((fc % MOD) *
              (((((modexp(2, u.ss) % MOD) + (modexp(2, dd1[{ax, bx}]) % MOD)) %
                 MOD) -
                1 + MOD) %
               MOD)) %
             MOD;
      } else
        fc = ((fc % MOD) * (modexp(2, u.ss) % MOD)) % MOD;
    }
  }
  fc = ((fc % MOD) - 1 + MOD) % MOD;
  cout << fc << "\\n";
  return;
}

int main(void) {
  FLASH();
  // freopen("cowjog.in", "r", stdin);
  // freopen("cowjog.out", "w", stdout);
  int T;
  T = 1;

#ifndef ONLINE_JUDGE
  time_t time_t1, time_t2;
  time_t1 = clock();
#endif

  // cin>>T;
  while (T--)
    solve(T);

#ifndef ONLINE_JUDGE
  time_t2 = clock();
  SETF();
  cerr << "Time taken: " << setprecision(7)
       << (time_t2 - time_t1) / (double)CLOCKS_PER_SEC << "\\n";
  UNSETF();
#endif

  return 0;
}