// need #include #include // data structure #include //#include #include #include #include #include #include #include #include //#include //#include #include #include #include //#include #include // stream //#include //#include //#include // etc #include #include #include //#include #include #include #include #define INIT std::ios::sync_with_stdio(false);std::cin.tie(0); #define VAR(type, ...)type __VA_ARGS__;MACRO_VAR_Scan(__VA_ARGS__); template void MACRO_VAR_Scan(T& t) { std::cin >> t; } templatevoid MACRO_VAR_Scan(First& first, Rest&...rest) { std::cin >> first; MACRO_VAR_Scan(rest...); } #define VEC_ROW(type, n, ...)std::vector __VA_ARGS__;MACRO_VEC_ROW_Init(n, __VA_ARGS__); for(int i=0; i void MACRO_VEC_ROW_Init(int n, T& t) { t.resize(n); } templatevoid MACRO_VEC_ROW_Init(int n, First& first, Rest&...rest) { first.resize(n); MACRO_VEC_ROW_Init(n, rest...); } template void MACRO_VEC_ROW_Scan(int p, T& t) { std::cin >> t[p]; } templatevoid MACRO_VEC_ROW_Scan(int p, First& first, Rest&...rest) { std::cin >> first[p]; MACRO_VEC_ROW_Scan(p, rest...); } #define OUT(d) std::cout< c(n);for(auto& i:c)std::cin>>i; #define MAT(type, c, m, n) std::vector> c(m, std::vector(n));for(auto& r:c)for(auto& i:r)std::cin>>i; #define ALL(a) (a).begin(),(a).end() #define FOR(i, a, b) for(int i=(a);i<(b);++i) #define RFOR(i, a, b) for(int i=(b)-1;i>=(a);--i) #define REP(i, n) for(int i=0;i=0;--i) #define FORLL(i, a, b) for(ll i=ll(a);i=ll(a);--i) #define REPLL(i, n) for(ll i=0;i=0;--i) #define PAIR std::pair #define PAIRLL std::pair #define IN(a, x, b) (a<=x && x tmp(a);std::cerr << #a << "\t:";for(int i=0; i(a.size()); ++i){std::cerr << tmp.front() << "\n";tmp.pop();}std::cerr << "\n";} template inline T CHMAX(T& a, const T b) { return a = (a < b) ? b : a; } template inline T CHMIN(T& a, const T b) { return a = (a > b) ? b : a; } #define EXCEPTION(msg) throw std::string("Exception : " msg " [ in ") + __func__ + " : " + std::to_string(__LINE__) + " lines ]" #define TRY(cond, msg) try {if (cond) EXCEPTION(msg);}catch (std::string s) {std::cerr << s << std::endl;} void CHECKTIME(std::function f) { auto start = std::chrono::system_clock::now(); f(); auto end = std::chrono::system_clock::now(); auto res = std::chrono::duration_cast((end - start)).count(); std::cerr << "[Time:" << res << "ns (" << res / (1.0e9) << "s)]\n"; } #define int ll using ll = long long; using ull = unsigned long long; constexpr int INFINT = 1 << 30; // 1.07x10^ 9 constexpr int INFINT_LIM = (1LL << 31) - 1; // 2.15x10^ 9 constexpr ll INFLL = 1LL << 60; // 1.15x10^18 constexpr ll INFLL_LIM = (1LL << 62) - 1 + (1LL << 62); // 9.22x10^18 constexpr double EPS = 1e-7; constexpr int MOD = 1000000007; constexpr double PI = 3.141592653589793238462643383279; //Union-Find class UnionFind { private: std::vector parent; std::vector height; std::vector m_size; public: UnionFind(int size_) : parent(size_), height(size_, 0), m_size(size_, 1) { REP(i, size_) { parent[i] = i; } } void init(int size_) { parent.resize(size_); height.resize(size_, 0); m_size.resize(size_, 0); REP(i, size_) { parent[i] = i; } } int find(int x) { if (parent[x] == x) { return x; } return parent[x] = find(parent[x]); } void unite(int x, int y) { x = find(x); y = find(y); if (x == y) return; int t = size(x) + size(y); m_size[x] = m_size[y] = t; if (height[x] < height[y]) parent[x] = y; else parent[y] = x; if (height[x] == height[y]) ++height[x]; } bool same(int x, int y) { return find(x) == find(y); } int size(int x) { if (parent[x] == x) { return m_size[x]; } return size(parent[x] = find(parent[x])); } }; int dy4[] = { -1, 0, 1, 0 }; int dx4[] = { 0, 1, 0, -1 }; int dy8[] = { -1, -1, -1, 0, 1, 1, 1, 0 }; int dx8[] = { -1, 0, 1, 1, 1, 0, -1, -1 }; // f=e-v+1 signed main() { INIT; VAR(int, n); auto f = [&](int y, int x) { return y * 100 + x; }; UnionFind uf(10000); std::vector node(10000); std::set ssset; REP(i, n) { /* 3 4 2 1 */ VAR(int, r0, c0, r1, c1); uf.unite(f(--r0, --c0), f(--r1, --c1)); ssset.insert(f(r0, c0)); ssset.insert(f(r1, c1)); int r = r0 - r1, c = c0 - c1; if (r == 1 && c == 0) { node[f(r0, c0)] |= (1 << 1); node[f(r1, c1)] |= (1 << 3); } else if (r == -1 && c == 0) { node[f(r0, c0)] |= (1 << 3); node[f(r1, c1)] |= (1 << 1); } else if (r == 0 && c == 1) { node[f(r0, c0)] |= (1 << 4); node[f(r1, c1)] |= (1 << 2); } else if (r == 0 && c == -1) { node[f(r0, c0)] |= (1 << 2); node[f(r1, c1)] |= (1 << 4); } } std::vector visited(10000); REP(i, 100) REP(j, 100) { if (visited[f(i, j)]) continue; if (uf.size(f(i, j)) == 1) continue; int e = 0, v = 0; std::set set; std::queue que; que.push(f(i, j)); visited[f(i, j)] = true; while (!que.empty()) { int now = que.front(); que.pop(); set.insert(now); int ni = now / 100, nj = now % 100; REP(d, 4) { int di = ni + dy4[d]; int dj = nj + dx4[d]; if (!IN(0, di, 100) || !IN(0, dj, 100)) continue; if (node[now] & (1 << (d + 1))) ++e; if (!visited[f(di, dj)] && (node[now] & (1 << (d+1)))) { visited[f(di, dj)] = true; que.push(f(di, dj)); } } } v = set.size(); e /= 2; if (e - v + 1 >= 2) { OUT("NO")BR; return 0; } } OUT("YES")BR; return 0; }