Language: C++

#include <bits/stdc++.h>
using namespace std;
#define rep(i, n)  for(long long i=0;i<(long long)(n);i++)
#define REP(i,k,n) for(long long i=k;i<(long long)(n);i++)
#define all(a) a.begin(),a.end()
#define pb emplace_back
#define eb emplace_back
#define lb(v,k) (lower_bound(all(v),k)-v.begin())
#define ub(v,k) (upper_bound(all(v),k)-v.begin())
#define fi first
#define se second
#define pi M_PI
#define PQ(T) priority_queue<T>
#define SPQ(T) priority_queue<T,vector<T>,greater<T>>
#define dame(a) {out(a);return 0;}
#define decimal cout<<fixed<<setprecision(15);
#define dupli(a) a.erase(unique(all(a)),a.end())
typedef long long ll;
typedef pair<ll,ll> P;
typedef tuple<ll,ll,ll> PP;
typedef tuple<ll,ll,ll,ll> PPP;
typedef multiset<ll> S;
using vi=vector<ll>;
using vvi=vector<vi>;
using vvvi=vector<vvi>;
using vvvvi=vector<vvvi>;
using vp=vector<P>;
using vvp=vector<vp>;
using vb=vector<bool>;
using vvb=vector<vb>;
const ll inf=1001001001001001001;
const ll INF=1001001001;
const ll mod=1000000007;
const double eps=1e-10;
template<class T> bool chmin(T&a,T b){if(a>b){a=b;return true;}return false;}
template<class T> bool chmax(T&a,T b){if(a<b){a=b;return true;}return false;}
template<class T> void out(T a){cout<<a<<'\n';}
template<class T> void outp(T a){cout<<'('<<a.fi<<','<<a.se<<')'<<'\n';}
template<class T> void outvp(T v){rep(i,v.size())cout<<'('<<v[i].fi<<','<<v[i].se<<')';cout<<'\n';}
template<class T> void outvvp(T v){rep(i,v.size())outvp(v[i]);}
template<class T> void outv(T v){rep(i,v.size()){if(i)cout<<' ';cout<<v[i];}cout<<'\n';}
template<class T> void outvv(T v){rep(i,v.size())outv(v[i]);}
template<class T> bool isin(T x,T l,T r){return (l)<=(x)&&(x)<=(r);}
template<class T> void yesno(T b){if(b)out("yes");else out("no");}
template<class T> void YesNo(T b){if(b)out("Yes");else out("No");}
template<class T> void YESNO(T b){if(b)out("YES");else out("NO");}
template<class T> void noyes(T b){if(b)out("no");else out("yes");}
template<class T> void NoYes(T b){if(b)out("No");else out("Yes");}
template<class T> void NOYES(T b){if(b)out("NO");else out("YES");}
void outs(ll a,ll b){if(a>=inf-100)out(b);else out(a);}
ll gcd(ll a,ll b){if(b==0)return a;return gcd(b,a%b);}
ll modpow(ll a,ll b){a%=mod;if(b==0)return 1;if(b&1)return a*modpow(a,b-1)%mod;ll k=modpow(a,b/2);return k*k%mod;}

int main(){
    ll n;cin>>n;
    vector<PP> v;
    ll ans=0,za=0,zb=0;
    rep(i,n){
        ll a,b;cin>>a>>b;
        if(b<0){
            a*=-1;b*=-1;
        }
        if(a==0&&b==0)ans++;
        else if(a==0)za++;
        else if(b==0)zb++;
        ll g=gcd(abs(a),abs(b));
        a/=g;b/=g;
        else if(a>0&&b>0)v.pb(a,b,0);
        else v.pb(-a,b,1);
    }
    sort(all(v));
    ll res=(modpow(2,za)+modpow(2,zb)+mod-1)%mod;
    n=v.size();
    int w=0;
    while(w<n){
        vi sum(2);
        int i=w+1;
        ll x,y,z;tie(x,y,z)=v[w];
        sum[z]++;
        while(i<n){
            ll a,b,c;
            tie(a,b,c)=v[i];
            if(x==a&&y==b)sum[c]++;
            else break;
            i++;
        }
        res*=(modpow(2,sum[0])+modpow(2,sum[1])+mod-1)%mod;
        res%=mod;
        w=i;
    }
    out((res+ans-1+mod)%mod);
}

Compiler output:
a.cc: In function 'int main()':
a.cc:68:9: error: 'else' without a previous 'if'
   68 |         else if(a>0&&b>0)v.pb(a,b,0);
      |         ^~~~