#ifndef MY_HEADER #define MY_HEADER #include #include using namespace std; using namespace atcoder; using lint = long long; using ulint = unsigned long long; using llint = __int128_t; struct edge; using graph = vector>; #define endl '\n' constexpr int INF = 1<<30; constexpr lint INF64 = 1LL<<61; constexpr lint mod107 = 1e9+7; using mint107 = modint1000000007; constexpr long mod = 998244353; using mint = modint998244353; lint ceilDiv(lint x, lint y){if(x >= 0){return (x+y-1)/y;}else{return x/y;}} lint floorDiv(lint x, lint y){if(x >= 0){return x/y;}else{return (x-y+1)/y;}} lint Sqrt(lint x) {assert(x >= 0); lint ans = sqrt(x); while(ans*ans > x)ans--; while((ans+1)*(ans+1)<=x)ans++; return ans;} lint gcd(lint a,lint b){if(a 0){int a = n%10;char b = '0' + a;string c = "";c += b;n /= 10;ans = c + ans;}}return ans;} string toString(lint n, lint k){string ans = toString(n);string tmp = "";while(ans.length() + tmp.length() < k){tmp += "0";}return tmp + ans;} vectorprime;void makePrime(lint n){prime.push_back(2);for(lint i=3;i<=n;i+=2){bool chk = true;for(lint j=0;j= 0; i--) #define vec vector #define pb push_back #define eb emplace_back #define se second #define fi first #define al(x) x.begin(),x.end() #define ral(x) x.rbegin(),x.rend() struct edge{ edge(lint v, lint c = 1) {to = v, cost = c;} lint to; lint cost; }; #endif struct Point { long long x, y; int quad; Point(long long X, long long Y) { x = X; y = Y; quad = getQuad(); } int getQuad() { if(x >= 0) { if(y >= 0) return 1; else return 4; } else { if(y >= 0) return 2; else return 3; } } }; bool operator<(const Point &left, const Point &right) { if(left.quad == right.quad) { return left.y * right.x < left.x * right.y; } else { return left.quad < right.quad; } } int main(){ lint N; cin >> N; vecX(N), Y(N); vec>P; rep(i, N) { cin >> X[i] >> Y[i]; P.pb({X[i], Y[i]}); } sort(al(P)); vecQ; rep(i, N){ X[i] -= P[0].first; Y[i] -= P[0].second; Q.eb(X[i], Y[i]); } sort(al(Q)); lint yminn = INF64; int t = -1; rep(i, N) { if(yminn > Q[i].y) { yminn = Q[i].y; t = i; } } // cerr << "t: " << t << endl; // rep(i, N) { // cout << Q[(i+t)%N].x << " " << Q[(i+t)%N].y << endl; // } rep(i, N-1) { Point p2(Q[(i+2+t)%N].x - Q[(t+i+1)%N].x, Q[(t+i+2)%N].y - Q[(t+i+1)%N].y); Point p1(Q[(i+1+t)%N].x - Q[(i+t)%N].x, Q[(t+i+1)%N].y - Q[(i+t)%N].y); if(p1 < p2) continue; cout << "No" << endl; return 0; } cout << "Yes" << endl; }