101684: [AtCoder]ABC168 E - ∙ (Bullet)
Memory Limit:256 MB
Time Limit:2 S
Judge Style:Text Compare
Creator:
Submit:0
Solved:0
Description
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