Forest

input/code.cpp: In function 'int main()':
input/code.cpp:10:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
                 ^
input/code.cpp:13:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &ux, &uy);
                          ^
input/code.cpp:19:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &x, &y);
                         ^

#include <cstdio>
#include <vector>
#include <algorithm>

using namespace std;

int main() {

	int n;
	scanf("%d", &n);

	int ux, uy;
	scanf("%d %d", &ux, &uy);

	vector<pair<int,int>> trees;

	for (int i = 0; i < n; ++i) {
		int x, y;
		scanf("%d %d", &x, &y);
		trees.emplace_back(x-ux, y-uy);
	}

	int v = 0;

	for (auto t1 : trees) {
		bool s = true;
		for (auto t2 : trees) {
			int x1 = t1.first, y1 = t1.second, x2 = t2.first, y2 = t2.second;
			if (x1 != x2 || y1 != y2) {
				if (((x1 == x2) && (abs(y1) < abs(y2))) || ((y1 == y2) && (abs(x1) < abs(x2)))) {
					s = false;
					break;
				}
				if (((x1 < 0) == (x2 < 0)) && ((y1 < 0) == (y2 < 0))) {
					if (((x1 - x2) < 0) == ((y1 - y2) < 0)) {
						if (abs(x1) <= abs(x2)) {
							if (x1 != 0 && y1 != 0 && ((abs(x2) % abs(x1)) == 0) && ((abs(y2) % abs(y1)) == 0)) {
								s = false;
								break;
							}
						}
					}
				}
			}
		}
		if (s) ++v;
	}

	printf("%d\n", v);

	return 0;
}

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: WRONG ANSWER

Test 17

Verdict: WRONG ANSWER

Test 18

Verdict: WRONG ANSWER

Test 19

Verdict: WRONG ANSWER

Test 20

Verdict: WRONG ANSWER