Forest

#include <iostream>
#include <set>

#define mp make_pair

using namespace std;

int n;
int ux,uy;
int x,y;
set<pair<int,int>> s;

int gcd(int a, int b) {
	if (a==0) return b;
	if (b==0) return a;
	return gcd(b, a%b);
}

int main() {
	cin >> n >> ux >> uy;
	for (int i=0;i<n;i++) {
		cin >> x >> y;
		x-=ux; y-=uy;
		int tmp = gcd(x,y);
		x/=tmp; y/=tmp;
		s.insert(mp(x,y));
	}
	cout << s.size() << "\n";
}

Test 1

Verdict: WRONG ANSWER

Test 2

Verdict: WRONG ANSWER

Test 3

Verdict: WRONG ANSWER

Test 4

Verdict: WRONG ANSWER

Test 5

Verdict: WRONG ANSWER

Test 6

Verdict: WRONG ANSWER

Test 7

Verdict: WRONG ANSWER

Test 8

Verdict: WRONG ANSWER

Test 9

Verdict: WRONG ANSWER

Test 10

Verdict: WRONG ANSWER

Test 11

Verdict: WRONG ANSWER

Test 12

Verdict: WRONG ANSWER

Test 13

Verdict: WRONG ANSWER

Test 14

Verdict: WRONG ANSWER

Test 15

Verdict: WRONG ANSWER

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED