AcWing 4299. Delete point

In a two-dimensional plane there is nn A little bit , None of these points are located in yy On the shaft .

Please judge whether there is any satisfaction in these points , After deleting this point , All the remaining points are in yy Same side of shaft .

Input format

The first line contains integers nn.

Next nn That's ok , Each line contains two integers x,yx,y, Represents the abscissa and ordinate of one of the points .

The positions of the points do not coincide .

Output format

If there are points that meet the requirements , The output Yes, Otherwise output No.

Data range

The first three test points meet  2≤n≤102≤n≤10.
All test points meet  2≤n≤1002≤n≤100,|x|,|y|≤100|x|,|y|≤100,|x|≠0|x|≠0.

sample input 1：

3
1 1
-1 -1
2 -1

sample output 1：

Yes

sample input 2：

4
1 1
2 2
-1 1
-2 2

sample output 2：

No

sample input 3：

3
1 2
2 1
4 60

sample output 3：

Yes

The code is as follows ：

#include<iostream>
#include<cstring>
using namespace std;

int n, cnt1, cnt2;

int main() {
	ios::sync_with_stdio(false);
	cout.tie(NULL);

	cin >> n;

	for(int i = 0; i < n; i ++) {
		int x, y;
		cin >> x >> y;
		if(x > 0)	cnt1++;
		else	cnt2++;
	}

	if(cnt1 == 1 || cnt2 == 1 || cnt1 == 0 || cnt2 == 0)
		cout<<"Yes";
	else
		cout<<"No";

	return 0;
}