参考文献
C++ 代码
#include<bits/stdc++.h>
using namespace std;
int main()
{
int n,i,a=0,b=0;
cin>>n;
for(i=1;i<=n;i++) {
int x;
int y;
cin>>x>>y;
if(x>0)a++;
else b++;
}
if(a<=1||b<=1)cout<<"Yes";
else cout<<"No";
}