Submission #1689859

---

Source Code Expand

#include<iostream>
#include<string.h>
#include<ctype.h>
#include<string>
#include<math.h>
#include<iomanip>
#include<algorithm>
#include<vector>
#include<stack>
#include<queue>
#define pi 3.141592653589
#define rep(i,a,n) for(int i=a;i<n;i++)
#define INF 1e9
#define LINF 1e17
#define ll long long
#define MOD (int)(1e9+7)
#define pii pair<int,int>
using namespace std;

int dx[4] = { 0,1,0,-1 };
int dy[4] = { 1,0,-1,0 };



int main() {

	ll n;
	pair<ll, ll> pll[100];
	int ans = 0;

	cin >> n;
	rep(i, 0, n)cin >> pll[i].first >> pll[i].second;
	sort(pll, pll + n);
	rep(i, 0, n - 2) {
		rep(j, i + 1, n - 1) {
			rep(k, j + 1, n) {
				if ((double)(pll[k].first - pll[j].first) / (pll[j].first - pll[i].first)
					!= (double)(pll[k].second - pll[j].second) / (pll[j].second - pll[i].second)) {
					ll fx = pll[j].first - pll[i].first;
					ll fy = pll[j].second - pll[i].second;
					ll gx = pll[k].first - pll[i].first;
					ll gy = pll[k].second - pll[i].second;
					ll s = abs(fx*gy - fy*gx);
					if ((s % 2 == 0) && (s != 0)) {
						ans++;
					}
				}
			}
		}
	}
	cout << ans << endl;

	return 0;
}

Submission Info

Judge Result