#include #include #include #include #include #include #include #include #include #include using namespace std; using namespace atcoder; #define ll long long #define INF 1000000000000000000 //namespace atcoder { vector ans(200010,-1); struct _edge { int to, rev; ll cap; }; template struct mf_graph { public: mf_graph() : _n(0) {} mf_graph(int n) : _n(n), g(n) {} int add_edge(int from, int to, Cap cap) { assert(0 <= from && from < _n); assert(0 <= to && to < _n); assert(0 <= cap); int m = int(pos.size()); pos.push_back({from, int(g[from].size())}); int from_id = int(g[from].size()); int to_id = int(g[to].size()); if (from == to) to_id++; g[from].push_back(_edge{to, to_id, cap}); g[to].push_back(_edge{from, from_id, 0}); return m; } struct edge { int from, to; Cap cap, flow; }; edge get_edge(int i) { int m = int(pos.size()); assert(0 <= i && i < m); auto _e = g[pos[i].first][pos[i].second]; auto _re = g[_e.to][_e.rev]; return edge{pos[i].first, _e.to, _e.cap + _re.cap, _re.cap}; } Cap flow(int s, int t) { return flow(s, t, std::numeric_limits::max()); } Cap flow(int s, int t, Cap flow_limit) { assert(0 <= s && s < _n); assert(0 <= t && t < _n); assert(s != t); std::vector level(_n), iter(_n); internal::simple_queue que; auto bfs = [&]() { std::fill(level.begin(), level.end(), -1); level[s] = 0; que.clear(); que.push(s); while (!que.empty()) { int v = que.front(); que.pop(); for (auto e : g[v]) { if (e.cap == 0 || level[e.to] >= 0) continue; level[e.to] = level[v] + 1; if (e.to == t) return; que.push(e.to); } } }; auto dfs = [&](auto self, int v, Cap up) { if (v == s) return up; Cap res = 0; int level_v = level[v]; for (int& i = iter[v]; i < int(g[v].size()); i++) { _edge& e = g[v][i]; if (level_v <= level[e.to] || g[e.to][e.rev].cap == 0) continue; Cap d = self(self, e.to, std::min(up - res, g[e.to][e.rev].cap)); if (d <= 0) continue; g[v][i].cap += d; g[e.to][e.rev].cap -= d; res += d; if (res == up) break; } return res; }; Cap flow = 0; while (flow < flow_limit) { bfs(); if (level[t] == -1) break; std::fill(iter.begin(), iter.end(), 0); while (flow < flow_limit) { Cap f = dfs(dfs, t, flow_limit - flow); if (!f) break; flow += f; } } return flow; } int _n; std::vector> pos; std::vector> g; }; //} // namespace atcoder int main(){ ll N,A,B; cin>>N; mf_graph F(2*N+2); for(int i=0;i>A>>B; A--;B--; F.add_edge(2*N,i,1); F.add_edge(i,N+A,1); if(A!=B)F.add_edge(i,N+B,1); F.add_edge(N+i,2*N+1,1); } ll cnt=F.flow(2*N,2*N+1); if(cnt!=N){ cout<<"No\n"; return 0; } cout<<"Yes\n"; for(int i=N;i<2*N;i++){ ll s=F.g.at(i).size(); for(int j=0;j