Language: C

#include <iostream>
#include <string>
#include <stack>
#include <queue>
#include <cctype>
#include <algorithm>
#include <vector>
#include <map>
#include <set>
#include <cmath>
#include <stdlib.h>
#include <tuple>
#include <iomanip>
#include <iterator>
#include <stdio.h>
#include <fstream>
#include <time.h>
using namespace std;
const double PI = 3.14159265358979323846;
const long long int MOD = 1000000000 + 7;

struct UnionFind {
    vector<int> parent;

    UnionFind(int N) : parent(N) {
        for (int i = 0; i < N; i++) {
            parent[i] = -1;
        }
    }

    int root(int i) {
        if (parent[i] < 0) {
            return i;
        }
        return (parent[i] = root(parent[i]));
    }

    bool unite(int from, int to) {
        int rx = root(from);
        int ry = root(to);
        if (rx != ry) {
            parent[ry] += parent[rx];
            parent[rx] = ry;

            return true;
        }
        else {
            return false;
        }
    }

    bool same(int x, int y) {
        return root(x) == root(y);
    }

    int treeSize(int x) {


        return -parent[root(x)];
    }
};

long long int modpow(long long int base, long long int pow, long long int mod) {
    if (pow == 1) {
        return base;
    }
    else if (pow == 0) {
        return 1;
    }

    if (pow % 2 == 0) {
        auto temp = modpow(base, pow / 2, mod);
        return (temp * temp) % mod;
    }
    else {
        return base * modpow(base, pow - 1, mod) % mod;
    }
}

long long int moddiv(long long int X, long long int Y, long long int mod) {
    auto fermatDiv = modpow(Y, mod - 2, mod);

    return (X * fermatDiv) % mod;
}

long long modCombination(long long left, long long right, long long int mod) {
    long long answer = 1;
    for (long long i = 0; i < right; i++) {
        answer = (answer * (left - i)) % mod;
        answer = moddiv(answer, (i + 1), mod);
    }

    return answer;
}

bool IsPrime(long long N) {
    if (N == 1) {
        return false;
    }
    for (long long i = 2; i * i <= N; i++) {
        if (N % i == 0) {
            return false;
        }
    }

    return true;
}



vector<pair<long long, long long> > prime_factorize(long long N) {
    vector<pair<long long, long long> > res;
    for (long long a = 2; a * a <= N; ++a) {
        if (N % a != 0) continue;
        long long ex = 0; // 指数

        // 割れる限り割り続ける
        while (N % a == 0) {
            ++ex;
            N /= a;
        }

        // その結果を push
        res.push_back({ a, ex });
    }

    // 最後に残った数について
    if (N != 1) res.push_back({ N, 1 });
    return res;
}

long long euclid(long long a, long long b) {
    if (a > b) {
        long long temp = b;
        b = a;
        a = temp;
    }
    if (b % a == 0) {
        return a;
    }
    else {
        return euclid(a, b - a);
    }
}

long long gcd(long long a, long long b) {
    if (b > a) {
        long long temp = b;
        b = a;
        a = temp;
    }
    //cout << "a:" << a << "b:" << b << endl;
    long long c = a % b;
    if (c == 0) {
        return b;
    }
    else {
        return gcd(b, c);
    }
}


int main() {
    int N;
    cin >> N;

    map<pair<long long, long long>, long long> bulletCounts;
    long long zzCount = 0;
    for (int i = 0; i < N; i++) {
        long long a, b;
        cin >> a >> b;

        if (a == 0 && b == 0) {
            zzCount++;
        }
        else {
            if (a == 0) {
                bulletCounts[make_pair(1, 0)]++;
               // cout << "1,0" << endl;
            }
            else if (b == 0) {
                bulletCounts[make_pair(0, -1)]++;
               // cout << "0, -1" << endl;
            }
            else if ((a > 0 && b > 0) || (a < 0 && b < 0)) {
                long long g = gcd(abs(a), abs(b));
                bulletCounts[make_pair(abs(a / g), abs(b / g))]++;
               // cout << abs(a / g) << "," << abs(b / g) << endl;
            }
            else {
                long long g = gcd(abs(a), abs(b));
                //cout << "g:" << g << endl;
                bulletCounts[make_pair(-abs(a / g), abs(b / g))]++;
                //cout << -abs(a / g) << "," << abs(b / g) << endl;
            }
        }
    }

    vector<long long> twos(N + 1);
    twos[0] = 1;
    for (int i = 1; i <= N; i++) {
        twos[i] = (twos[i - 1] * 2) % MOD;
    }

    map < pair<long long, long long>, bool> isUsed;
    long long answer = 1;
    for (auto p : bulletCounts) {
        if (isUsed[p.first]) {
            continue;
        }

        auto rivalPair = make_pair(p.first.second, -p.first.first);

        long long rivals = 0;

        if (bulletCounts.count(rivalPair) > 0) {
            rivals = bulletCounts[rivalPair];
        }

        answer *= ((twos[p.second] % MOD) + (twos[rivals] % MOD) - 1) % MOD;
        // cout << p.first.first << "." << p.first.second << "." << twos[p.second] <<  ":"  << rivalPair.first << "." << rivalPair.second << "." << twos[rivals] << ":"<< answer << endl;
        isUsed[p.first] = true;
        isUsed[rivalPair] = true;
    }

    cout << (answer - 1 + zzCount) % MOD << endl;

    return 0;
}

Compiler output:
main.c:1:10: fatal error: iostream: No such file or directory
    1 | #include <iostream>
      |          ^~~~~~~~~~
compilation terminated.