long double加精度和输入输出流的关闭

#include<stdio.h>#include<stdlib.h>#include<string.h>#include<math.h>#include<iostream>#include<algorithm>#include<stack>#include<queue>#include<vector>#include<set>#include<map>#include<string>#define nl n<<1#define nr (n<<1)|1using namespace std;typedef long long ll;typedef pair<int,int>P;const int INF=0x3f3f3f3f;const ll INFF=0x3f3f3f3f3f3f3f3f;const double pi=acos(-1.0);const double eps=1e-9;const ll mod=1e9+7;set<long double>s;int main(){    ios::sync_with_stdio(false);    int n;    cin>>n;    for(int i=1;i<=n;i++)    {        long double k,b;        cin>>k>>b;        if(k)s.insert(b/k);    }    cout<<s.size()<<endl;    return 0;}