結果

問題 No.1144 Triangles
コンテスト
ユーザー heno239
提出日時 2020-07-31 23:09:29
言語 C++14
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 793 ms / 3,000 ms
コード長 3,953 bytes
コンパイル時間 1,317 ms
コンパイル使用メモリ 125,596 KB
実行使用メモリ 6,944 KB
最終ジャッジ日時 2024-07-06 21:01:59
合計ジャッジ時間 12,415 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge5
このコードへのチャレンジ
（要ログイン）
ファイルパターン 結果
sample AC * 4
other AC * 25
権限があれば一括ダウンロードができます

ソースコード

diff #
raw source code 

#include<iostream>
#include<string>
#include<cstdio>
#include<vector>
#include<cmath>
#include<algorithm>
#include<functional>
#include<iomanip>
#include<queue>
#include<ciso646>
#include<random>
#include<map>
#include<set>
#include<bitset>
#include<stack>
#include<unordered_map>
#include<utility>
#include<cassert>
#include<complex>
#include<numeric>
using namespace std;

//#define int long long
typedef long long ll;

typedef unsigned long long ul;
typedef unsigned int ui;
constexpr ll mod = 1000000007;
const ll INF = mod * mod;
typedef pair<int, int>P;
#define stop char nyaa;cin>>nyaa;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define per1(i,n) for(int i=n;i>=1;i--)
#define Rep1(i,sta,n) for(int i=sta;i<=n;i++)
#define all(v) (v).begin(),(v).end()
typedef pair<ll, ll> LP;
typedef long double ld;
typedef pair<ld, ld> LDP;
const ld eps = 1e-12;
const ld pi = acos(-1.0);

ll mod_pow(ll x, ll n, ll m) {
	ll res = 1;
	while (n) {
		if (n & 1)res = res * x % m;
		x = x * x % m; n >>= 1;
	}
	return res;
}
struct modint {
	ll n;
	modint() :n(0) { ; }
	modint(ll m) :n(m) {
		if (n >= mod)n %= mod;
		else if (n < 0)n = (n % mod + mod) % mod;
	}
	operator int() { return n; }
};
bool operator==(modint a, modint b) { return a.n == b.n; }
modint operator+=(modint& a, modint b) { a.n += b.n; if (a.n >= mod)a.n -= mod; return a; }
modint operator-=(modint& a, modint b) { a.n -= b.n; if (a.n < 0)a.n += mod; return a; }
modint operator*=(modint& a, modint b) { a.n = ((ll)a.n * b.n) % mod; return a; }
modint operator+(modint a, modint b) { return a += b; }
modint operator-(modint a, modint b) { return a -= b; }
modint operator*(modint a, modint b) { return a *= b; }
modint operator^(modint a, int n) {
	if (n == 0)return modint(1);
	modint res = (a * a) ^ (n / 2);
	if (n % 2)res = res * a;
	return res;
}

ll inv(ll a, ll p) {
	return (a == 1 ? 1 : (1 - p * inv(p % a, a)) / a + p);
}
modint operator/(modint a, modint b) { return a * modint(inv(b, mod)); }

const int max_n = 1 << 17;
modint fact[max_n], factinv[max_n];
void init_f() {
	fact[0] = modint(1);
	for (int i = 0; i < max_n - 1; i++) {
		fact[i + 1] = fact[i] * modint(i + 1);
	}
	factinv[max_n - 1] = modint(1) / fact[max_n - 1];
	for (int i = max_n - 2; i >= 0; i--) {
		factinv[i] = factinv[i + 1] * modint(i + 1);
	}
}
modint comb(int a, int b) {
	if (a < 0 || b < 0 || a < b)return 0;
	return fact[a] * factinv[b] * factinv[a - b];
}

void solve() {
	int n; cin >> n;
	vector<int> x(n), y(n);
	rep(i, n)cin >> x[i] >> y[i];
	auto calc = [&](int i, int j, int k) {
		return (x[j] - x[i]) * (y[k] - y[i]) - (x[k] - x[i]) * (y[j] - y[i]);
	};
	modint ans = 0;
	rep(s, n) {
		vector<pair<ld, int>> vs;
		rep(i, n)if (i != s) {
			ld t = atan2(y[i] - y[s], x[i] - x[s]);
			vs.push_back({ t,i });
		}
		sort(all(vs));
		int sz = n - 1;
		rep(i, sz)vs.push_back({ vs[i].first + 2 * pi,vs[i].second });
		vector<modint> rx(2 * sz + 1), ry(2 * sz + 1);
		rep(i, 2 * sz) {
			int id = vs[i].second;
			rx[i + 1] = rx[i] + (modint)x[id];
			ry[i + 1] = ry[i] + (modint)y[id];
		}
		int loc = 0;
		rep(i, sz) {
			int id = vs[i].second;
			while (vs[loc].first <= vs[i].first + pi) {
				loc++;
			}
			int cp = loc - i - 1;
			int cn = n - 2 - cp;
			ans += (ll)(cp - cn) * (x[s] * y[id] - y[s] * x[id]);
			ll sx = rx[loc] - rx[i + 1];
			ans += -sx * (y[id] - y[s]);
			ll sy = ry[loc] - ry[i + 1];
			ans += sy * (x[id] - x[s]);

			sx = rx[sz]-(modint)x[id] - (modint)sx;
			ans += sx * (y[id] - y[s]);
			sy = ry[sz]-(modint)y[id] - (modint)sy;
			ans -= sy * (x[id] - x[s]);
		}
		//cout << s << " " << ans << "\n";

	}
	ans *= (1 + mod) / 6;
	cout << ans << "\n";
}




signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	//cout << fixed << setprecision(10);
	//init_f();
	//init();
	//int t; cin >> t; rep(i, t)
	//init();
	solve();
	return 0;
}
0