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

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<bool> vb;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef map<int, int> mii;
typedef map<ll, ll> mll;
typedef vector<pii> vii;
typedef vector<pll> vll;
#define fi first
#define se second
#define pi 3.141592653589793
#define mod 1000000007
#define pb push_back
#define all(v) v.begin(), v.end()
#define tc                                                                     \\
  int t;                                                                       \\
  cin >> t;                                                                    \\
  while (t--)
#define pqmax priority_queue<int>
#define pqmin priority_queue<int, vi, greater<int>>
#define fast_io ios_base::sync_with_stdio(0), cin.tie(NULL)
#define tc_g                                                                   \\
  int tt;                                                                      \\
  cin >> tt;                                                                   \\
  for (int ti = 1; ti <= tt; ti++)
#define case_g "Case #" << ti << ": "
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
typedef tree<int, null_type, less_equal<int>, rb_tree_tag,
             tree_order_statistics_node_update>
    ordered_multiset;
typedef tree<int, null_type, less<int>, rb_tree_tag,
             tree_order_statistics_node_update>
    ordered_set;
typedef tree<int, int, less<int>, rb_tree_tag,
             tree_order_statistics_node_update>
    ordered_map;

int main() {
  fast_io;
  int N;
  cin >> N;
  ll pow2[N + 1];
  pow2[0] = 1;
  for (int i = 1; i <= N; i++)
    pow2[i] = pow2[i - 1] * 2 % mod;
  map<pll, int> p, n;
  int cntz = 0, l = 0, r = 0;
  for (int i = 0; i < N; i++) {
    ll a, b;
    cin >> a >> b;
    bool pos = 1;
    if (a < 0) {
      a = abs(a);
      pos = !pos;
    }
    if (b < 0) {
      b = abs(b);
      pos = !pos;
    }
    ll g = __gcd(a, b);
    if (g == 0) {
      cntz++;
      continue;
    }
    if (a == 0) {
      l++;
      continue;
    }
    if (b == 0) {
      r++;
      continue;
    }
    a /= g;
    b /= g;
    if (pos)
      p[{a, b}]++;
    else
      n[{a, b}]++;
  }
  ll ans = 1;
  N -= cntz;
  for (auto x : p) {
    int a = x.se;
    int b = n[{x.fi.se, x.fi.fi}];
    N -= (a + b);
    ans = ans * (pow2[a] + pow2[b] - 1) % mod;
  }
  ans = ans * (pow2[l] + pow2[r] - 1) % mod;
  N -= (l + r);
  ans = ans * pow2[N] % mod;
  cout << (ans + mod - 1 + cntz) % mod << '\\n';
}


Error: 0

Fixed submission:

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<bool> vb;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef map<int, int> mii;
typedef map<ll, ll> mll;
typedef vector<pii> vii;
typedef vector<pll> vll;
#define fi first
#define se second
#define pi 3.141592653589793
#define mod 1000000007
#define pb push_back
#define all(v) v.begin(), v.end()
#define tc                                                                     \\
  int t;                                                                       \\
  cin >> t;                                                                    \\
  while (t--)
#define pqmax priority_queue<int>
#define pqmin priority_queue<int, vi, greater<int>>
#define fast_io ios_base::sync_with_stdio(0), cin.tie(NULL)
#define tc_g                                                                   \\
  int tt;                                                                      \\
  cin >> tt;                                                                   \\
  for (int ti = 1; ti <= tt; ti++)
#define case_g "Case #" << ti << ": "
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
typedef tree<int, null_type, less_equal<int>, rb_tree_tag,
             tree_order_statistics_node_update>
    ordered_multiset;
typedef tree<int, null_type, less<int>, rb_tree_tag,
             tree_order_statistics_node_update>
    ordered_set;
typedef tree<int, int, less<int>, rb_tree_tag,
             tree_order_statistics_node_update>
    ordered_map;

int main() {
  fast_io;
  int N;
  cin >> N;
  ll pow2[N + 1];
  pow2[0] = 1;
  for (int i = 1; i <= N; i++)
    pow2[i] = pow2[i - 1] * 2 % mod;
  map<pll, int> p, n;
  for (int i = 0; i < N; i++) {
    ll a, b;
    cin >> a >> b;
    bool pos = 1;
    if (a < 0) {
      a = abs(a);
      pos = !pos;
    }
    if (b < 0) {
      b = abs(b);
      pos = !pos;
    }
    ll g = __gcd(a, b);
    a /= g;
    b /= g;
    if (pos)
      p[{a, b}]++;
    else
      n[{a, b}]++;
  }
  ll ans = 1;
  for (auto x : p) {
    int a = x.se;
    int b = n[{x.fi.se, x.fi.fi}];
    N -= (a + b);
    ans = ans * (pow2[a] + pow2[b] - 1) % mod;
  }
  ans = ans * pow2[N] % mod;
  cout << (ans + mod - 1) % mod << '\\n';
}