/* このコード、と~おれ! Be accepted! ∧_∧  (。・ω・。)つ━☆・*。 ⊂   ノ    ・゜+.  しーJ   °。+ *´¨)          .· ´¸.·*´¨) ¸.·*¨)           (¸.·´ (¸.·'* ☆ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include ////多倍長整数, cpp_intで宣言 //#include //using namespace boost::multiprecision; //#pragma gcc target ("avx2") //#pragma gcc optimization ("Ofast") //#pragma gcc optimization ("unroll-loops") #define rep(i, n) for(int i = 0; i < (n); ++i) #define rep1(i, n) for(int i = 1; i <= (n); ++i) #define rep2(i, n) for(int i = 2; i < (n); ++i) #define repr(i, n) for(int i = n; i >= 0; --i) #define reprm(i, n) for(int i = n - 1; i >= 0; --i) #define printynl(a) printf(a ? "yes\n" : "no\n") #define printyn(a) printf(a ? "Yes\n" : "No\n") #define printYN(a) printf(a ? "YES\n" : "NO\n") #define printim(a) printf(a ? "possible\n" : "imposible\n") #define printdb(a) printf("%.50lf\n", a) //少数出力 #define printLdb(a) printf("%.50Lf\n", a) //少数出力 #define printdbd(a) printf("%.16lf\n", a) //少数出力(桁少なめ) #define prints(s) printf("%s\n", s.c_str()) //string出力 #define all(x) (x).begin(), (x).end() #define deg_to_rad(deg) (((deg)/360.0L)*2.0L*PI) #define rad_to_deg(rad) (((rad)/2.0L/PI)*360.0L) #define Please return #define AC 0 #define manhattan_dist(a, b, c, d) (abs(a - c) + abs(b - d)) /*(a, b) から (c, d) のマンハッタン距離 */ #define inf numeric_limits::infinity(); #define linf numeric_limits::infinity() using ll = long long; using ull = unsigned long long; constexpr int INF = 1073741823; constexpr int MINF = -1073741823; constexpr ll LINF = ll(4661686018427387903); constexpr ll MOD = 1e9 + 7; constexpr long double eps = 1e-6; const long double PI = acosl(-1.0L); using namespace std; void scans(string& str) { char c; str = ""; scanf("%c", &c); if (c == '\n')scanf("%c", &c); while (c != '\n' && c != -1 && c != ' ') { str += c; scanf("%c", &c); } } void scanc(char& str) { char c; scanf("%c", &c); if (c == -1)return; while (c == '\n') { scanf("%c", &c); } str = c; } double acot(double x) { return PI / 2 - atan(x); } ll LSB(ll n) { return (n & (-n)); } /*-----------------------------------------ここからコード-----------------------------------------*/ /* * @title modint * @docs kyopro/docs/modint.md */ template struct modint { int val, size; vector fac, inv, facinv; modint() : val(0), size(0) {}; modint(ll x) : val(x >= 0 ? x % mod : (mod + x % mod) % mod), size(0) {}; //siz <= 1e7 くらい void cominit(const int siz) { size = siz; fac.assign(siz + 1, 0); inv.assign(siz + 1, 0); facinv.assign(siz + 1, 0); fac[0] = fac[1] = facinv[0] = facinv[1] = inv[0] = 1; for (ll i = 2; i <= siz; ++i) { fac[i] = fac[i - 1] * i % mod; inv[i] = mod - inv[mod % i] * (mod / i) % mod; facinv[i] = facinv[i - 1] * inv[i] % mod; } } modint& operator=(const modint& x) { val = x.val; return *this; } modint& operator+=(const modint& x) { val += x.val; if (val >= mod)val -= mod; return *this; } modint& operator-=(const modint& x) { val += mod - x.val; if (val >= mod)val -= mod; return *this; } modint& operator*=(const modint& x) { val = (int)((ll)val * (ll)x.val % mod); return *this; } modint& operator/=(const modint& x) { if (x.val <= size) { ll num = x.val; num *= inv[x.val]; num %= mod; val = num; return *this; } int a = x.val, b = mod, u = 1, v = 0, t; while (b > 0) { t = a / b; swap(a -= t * b, b); swap(u -= t * v, v); } *this *= modint(u); return *this; } modint operator++() { val = (val + 1 == mod ? 0 : val + 1); return *this; } modint operator--() { val = (val == 0 ? mod - 1 : val - 1); return *this; } modint operator+(const modint& x) const { return (modint(*this) += x); } modint operator-(const modint& x) const { return (modint(*this) -= x); } modint operator*(const modint& x) const { return (modint(*this) *= x); } modint operator/(const modint& x) const { return (modint(*this) /= x); } bool operator==(const modint& x)const { return (val == x.val); } bool operator!=(const modint& x)const { return (val != x.val); } bool operator<(const modint& x)const { return (val < x.val); } bool operator>(const modint& x)const { return (val > x.val); } modint pow(ll n) { modint ret(1), a(val); while (n > 0) { if (n % 2) ret *= a; a *= a; n /= 2; } return ret; } modint comb(const modint& n, const modint& r) { return (n < r or n < 0 or r < 0) ? 0 : ((fac[n] * (facinv[r] * facinv[n - r] % mod)) % mod); } static int getmod() { return mod; }; }; struct vector2D { int x, y; vector2D(int x, int y) : x(x), y(y) {} vector2D(int stx, int sty, int enx, int eny) : x(enx - stx), y(eny - sty) {} vector2D operator+(const vector2D p) { return vector2D(x + p.x, y + p.y); } vector2D operator-(const vector2D p) { return vector2D(x - p.x, y - p.y); } // スカラー倍 vector2D operator*(const int p) { return vector2D(x * p, y * p); } }; int vectorproduct(vector2D p, vector2D q) { return abs(p.x * q.y - p.y * q.x); } int main() { int n; scanf("%d", &n); vector> p(n); for (auto& [a, b] : p)scanf("%d%d", &a, &b); sort(all(p), [](const pair& p1, const pair& p2) { return atan2l(p1.second, p1.first) < atan2l(p2.second, p2.first); }); modint ans; vector2D a(p[0].first, p[0].second, p[1].first, p[1].second); vector b(n + 1, vector2D(0, 0)); rep(i, n) { b[i + 1] = b[i] + vector2D(p[0].first, p[0].second, p[i].first, p[i].second); } rep(i, n) { vector2D c(0, 0); for (int j = i + 1; j < n; ++j) { a = vector2D(p[i].first, p[i].second, p[j].first, p[j].second); c = b[n] - b[j]; c = c + vector2D(p[i].first, p[i].second, p[0].first, p[0].second) * (n - j); ans += vectorproduct(a, c); } } printf("%d\n", ans.val); Please AC; }