#include <bits/stdc++.h>
using namespace std;
using ld = long double;
using ll = long long;
const ld eps = 1e-8;
#define int ll
#define sz(x) (int)x.size()
struct point {
int x, y;
};
signed main(){
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n;
cin >> n;
vector<point> points(n);
vector<int> x(n), y(n);
for(int i=0; i<n; ++i){
cin >> points[i].x >> points[i].y;
x[i] = points[i].x;
y[i] = points[i].y;
}
int ans = 0;
for(int i=0; i<n; ++i){
for(int j=i+1; j<n; ++j){
// AB
bool ok = 1;
for(int k=0; k<n; ++k){
if(k == j or k == i) continue;
for(int l=k+1; l<n; ++l){
if(l == j or l == i) continue;
// CD
int xa = x[i];
int ya = y[i];
int xb = x[j];
int yb = y[j];
ld m1 = 1.0 * (ya - yb) / (xa - xb);
int xc = x[k];
int yc = y[k];
int xd = x[l];
int yd = y[l];
ld m2 = 1.0 * (yc - yd) / (xc - xd);
if(abs(m2 - m1) < eps){
continue;
}
ld x = 1.0 * (m1 * xa - m2 * xc + yc - ya) / (m1 - m2);
ld y = m1 * x - m1 * xa + ya;
if(min(xa, xb) <= x && x <= max(xa, xb) && min(ya, yb) <= y && y <= max(ya, yb) && min(xc, xd) <= x && x <= max(xc, xd) && min(yc, yd) <= y && y <= max(yc, yd)){
// cerr << "el segmento: " << xa << ya << ' ' << xb << yb << endl;
// cerr << "choca con el segmento " << xc << yc << ' ' << xd << yd << endl;
// cerr << "en " << x << ' ' << y << endl;
ok = 0;
}
}
}
ans += ok;
}
}
cout << ans;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
16 ms |
348 KB |
Output is correct |
2 |
Correct |
15 ms |
452 KB |
Output is correct |
3 |
Correct |
16 ms |
348 KB |
Output is correct |
4 |
Incorrect |
9 ms |
348 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
16 ms |
348 KB |
Output is correct |
2 |
Correct |
15 ms |
452 KB |
Output is correct |
3 |
Correct |
16 ms |
348 KB |
Output is correct |
4 |
Incorrect |
9 ms |
348 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
16 ms |
348 KB |
Output is correct |
2 |
Correct |
15 ms |
452 KB |
Output is correct |
3 |
Correct |
16 ms |
348 KB |
Output is correct |
4 |
Incorrect |
9 ms |
348 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |