제출 #1152684

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1152684		thelegendary08	Geometrija (COCI21_geometrija)	C++17	0 / 110	4 ms	320 KiB

geometrija

#include<bits/stdc++.h>
#define f0r(i,n) for(int i = 0; i<n; i++)
#define pb push_back
#define vi vector<long long int>
#define ll long long int
#define mp make_pair
#define pii pair<ll,ll>
#define FOR(i, k, n) for(int i = k; i<n; i++)
const double pi = 3.14159265358979;
using namespace std;
double dir(pii a, pii b){
	double x = atan((b.second - a.second) / (b.first - a.first + 0.0));
	return x;
}
bool side(pii a, pii b, pii c){
	//cout<<dir(a,b)<<' '<<dir(a,c)<<'\n';
	return (c.second-a.second) * (b.first - a.first) - (c.first-a.first) * (b.second - a.second) > 0; 
}
bool intersect(pii a, pii b, pii c, pii d){
	if(min(a.first, b.first) > max(c.first, d.first) || min(c.first, d.first) > max(a.first, b.first) || min(a.second, b.second) > max(c.first, d.first) || min(c.second, d.second) > max(a.second, b.second))return 0;
	else if(side(a,b,c) == side(a,b,d))return 0;
	return 1;
}
int main(){
	int n; cin>>n;
	vector<pii> v;
	f0r(i,n){
		int a,b;
		cin>>a>>b;
		v.pb({a,b});
	}
	//cout<<side(v[0],v[2],v[1])<<'\n';
	//cout<<side(v[0],v[2],v[3])<<'\n';
	int ans = 0;
	
	f0r(i,n){
		FOR(j, i+1, n){
			bool ok = 1;
			f0r(k, n){
				FOR(l, k+1, n){
					if(i != k && i != l && j != k && j != l){
						if(intersect(v[i], v[j], v[k], v[l])){
							
							ok = 0;
						}
					}
				}
			}
			
			if(ok){
				ans++;
				//cout<<i<<' '<<j<<'\n';
			}
		}
	}
	
	cout<<ans<<'\n';
}

• Subtask 1: 0 / 20
• Subtask 2: 0 / 30
• Subtask 3: 0 / 60