Problem:
Score: 500 points

Problem Statement

We have caught N sardines. The deliciousness and fragrantness of the i-th sardine is A_i and B_i, respectively.

We will choose one or more of these sardines and put them into a cooler. However, two sardines on bad terms cannot be chosen at the same time.

The i-th and j-th sardines (i \neq j) are on bad terms if and only if A_i \cdot A_j + B_i \cdot B_j = 0.

In how many ways can we choose the set of sardines to put into the cooler? Since the count can be enormous, print it modulo 1000000007.

Constraints

All values in input are integers.

1 \leq N \leq 2 \times 10^5

-10^{18} \leq A_i, B_i \leq 10^{18}

Input

Input is given from Standard Input in the following format:

N
A_1 B_1
:
A_N B_N

Output

Print the count modulo 1000000007.

Sample Input 1

3
1 2
-1 1
2 -1

Sample Output 1

5

There are five ways to choose the set of sardines, as follows:

The 1-st

The 1-st and 2-nd

The 2-nd

The 2-nd and 3-rd

The 3-rd

Sample Input 2

10
3 2
3 2
-1 1
2 -1
-3 -9
-8 12
7 7
8 1
8 2
8 4

Sample Output 2

479

Solution in Rust (1.42.0) (judge verdict: Accepted)

#[allow(unused_imports)]
use std::char::from_digit;
use std::cmp::{max, min};
use std::collections::{BTreeMap, BTreeSet, BinaryHeap, HashMap, HashSet, VecDeque};
use std::error::Error;
use std::fmt::Debug;
use std::io::prelude::*;
use std::io::{stdin, stdout, BufReader, BufWriter, Stdin, Stdout, Write};
use std::mem::swap;
use std::str::FromStr;

type BoxResult<T> = Result<T, Box<std::error::Error>>;

const MOD: u64 = 1000000007;

fn main() {
    let mut scanner = Scanner::new(stdin());
    let n = scanner.read::<usize>().unwrap();
    let mut items = vec![];
    for _ in 0..n {
        items.push(scanner.read_two::<i64, i64>().unwrap());
    }
    let ans = solve(n, &items);
    println!("{}", ans);
}

fn solve(_n: usize, items: &[(i64, i64)]) -> u64 {
    let mut map = HashMap::new();
    for &(a, b) in items {
        let key = encode(a, b);
        if map.contains_key(&key) {
            *map.get_mut(&key).unwrap() += 1;
        } else {
            map.insert(key, 1u64);
        }
    }
    // println!("{:?}", map);
    let mut count = 1u64;
    let mut used = HashSet::new();
    for (&key, &value) in map.iter() {
        if used.contains(&key) {
            continue;
        }
        used.insert(key);
        if key == (0, 0) {
            continue;
        }
        let mut total = power(2, value, MOD);
        let anti_key = calc_anti(key);
        if map.contains_key(&anti_key) {
            let c = map.get(&anti_key).unwrap();
            total = (total + power(2, *c, MOD) + MOD - 1) % MOD;
            used.insert(anti_key);
        }
        count = (count * total) % MOD;
    }
    let zeros = map.get(&(0, 0)).unwrap_or(&0);
    (count + MOD - 1 + *zeros) % MOD
}

fn encode(a: i64, b: i64) -> (i64, i64) {
    let (c, d) = if a == 0 && b != 0 {
        (0, 1)
    } else if b == 0 && a != 0 {
        (1, 0)
    } else if a < 0 {
        (-a, -b)
    } else {
        (a, b)
    };
    let g = gcd(c.abs(), d.abs());
    (c / g, d / g)
}

fn gcd(x: i64, y: i64) -> i64 {
    if x == 0 || y == 0 {
        return 1;
    }
    let z = x % y;
    if z == 0 {
        y
    } else {
        gcd(y, z)
    }
}

fn power(x: u64, mut k: u64, modulo: u64) -> u64 {
    let mut pows = vec![x];
    for i in 0..63 {
        let square = (pows[i] * pows[i]) % modulo;
        pows.push(square);
    }
    let mut pow = 1;
    for i in 0..63 {
        let flag = k & 1;
        k >>= 1;
        if flag == 1 {
            pow = (pow * pows[i]) % modulo;
        }
    }
    pow
}

fn calc_anti((x, y): (i64, i64)) -> (i64, i64) {
    let mut a = -y;
    let mut b = x;
    if a < 0 {
        a *= -1;
        b *= -1;
    }
    (a, b)
}

pub struct Scanner<R> {
    reader: BufReader<R>,
    buffer: String,
}
impl<R> Scanner<R>
where
    R: Read,
{
    pub fn new(inner: R) -> Scanner<R> {
        let reader = BufReader::new(inner);
        let buffer = String::new();
        Scanner {
            reader: reader,
            buffer: buffer,
        }
    }
    pub fn with_capacity(capacity: usize, inner: R) -> Scanner<R> {
        let reader = BufReader::with_capacity(capacity, inner);
        let buffer = String::new();
        Scanner {
            reader: reader,
            buffer: buffer,
        }
    }
    pub fn read_line(&mut self) -> BoxResult<String> {
        self.reader.read_line(&mut self.buffer)?;
        let cloned = self.buffer.trim().to_string();
        self.buffer.clear();
        Ok(cloned)
    }

    pub fn read<T>(&mut self) -> BoxResult<T>
    where
        T: FromStr,
        T::Err: Debug + Error + 'static,
    {
        self.reader.read_line(&mut self.buffer)?;
        let parsed = self.buffer.trim().parse()?;
        self.buffer.clear();
        Ok(parsed)
    }
    pub fn read_two<T, U>(&mut self) -> BoxResult<(T, U)>
    where
        T: FromStr + Copy,
        T::Err: Debug + Error + 'static,
        U: FromStr + Copy,
        U::Err: Debug + Error + 'static,
    {
        self.reader.read_line(&mut self.buffer)?;
        let (a, b) = {
            let params = self.buffer.trim().split_whitespace().collect::<Vec<_>>();
            let a = params[0].parse()?;
            let b = params[1].parse()?;
            (a, b)
        };
        self.buffer.clear();
        Ok((a, b))
    }
    pub fn read_three<T, U, V>(&mut self) -> BoxResult<(T, U, V)>
    where
        T: FromStr + Copy,
        T::Err: Debug + Error + 'static,
        U: FromStr + Copy,
        U::Err: Debug + Error + 'static,
        V: FromStr + Copy,
        V::Err: Debug + Error + 'static,
    {
        self.reader.read_line(&mut self.buffer)?;
        let (a, b, c) = {
            let params = self.buffer.trim().split_whitespace().collect::<Vec<_>>();
            let a = params[0].parse()?;
            let b = params[1].parse()?;
            let c = params[2].parse()?;
            (a, b, c)
        };
        self.buffer.clear();
        Ok((a, b, c))
    }
    pub fn read_four<T, U, V, W>(&mut self) -> BoxResult<(T, U, V, W)>
    where
        T: FromStr + Copy,
        T::Err: Debug + Error + 'static,
        U: FromStr + Copy,
        U::Err: Debug + Error + 'static,
        V: FromStr + Copy,
        V::Err: Debug + Error + 'static,
        W: FromStr + Copy,
        W::Err: Debug + Error + 'static,
    {
        self.reader.read_line(&mut self.buffer)?;
        let (a, b, c, d) = {
            let params = self.buffer.trim().split_whitespace().collect::<Vec<_>>();
            let a = params[0].parse()?;
            let b = params[1].parse()?;
            let c = params[2].parse()?;
            let d = params[3].parse()?;
            (a, b, c, d)
        };
        self.buffer.clear();
        Ok((a, b, c, d))
    }
    pub fn read_vector<T>(&mut self) -> BoxResult<Vec<T>>
    where
        T: FromStr + Copy,
        T::Err: Debug + Error + 'static,
    {
        self.reader.read_line(&mut self.buffer)?;
        let parsed_vec = self
            .buffer
            .trim()
            .split_whitespace()
            .map(|s| s.parse())
            .collect::<Result<Vec<_>, _>>()?;
        self.buffer.clear();
        Ok(parsed_vec)
    }
    pub fn read_matrix<T>(&mut self, lines: u64) -> BoxResult<Vec<Vec<T>>>
    where
        T: FromStr + Copy,
        T::Err: Debug + Error + 'static,
    {
        let mut parsed_matrix = vec![];
        for _ in 0..lines {
            self.reader.read_line(&mut self.buffer)?;
            parsed_matrix.push(
                self.buffer
                    .trim()
                    .split_whitespace()
                    .map(|s| s.parse())
                    .collect::<Result<Vec<_>, _>>()?,
            );
            self.buffer.clear();
        }
        Ok(parsed_matrix)
    }
    pub fn read_chars(&mut self) -> BoxResult<Vec<char>> {
        self.reader.read_line(&mut self.buffer)?;
        let chars = self.buffer.trim().chars().collect::<Vec<_>>();
        self.buffer.clear();
        Ok(chars)
    }
}