#include #include #include #include #include #include #include #include #include #include #include using namespace std; typedef long long ll; const int MAX_N = 200000; vector parent; vector _rank; vector _size; class UnionFind { public: UnionFind(int n) { for (int i = 0; i < n; ++i) { parent.push_back(i); _rank.push_back(0); _size.push_back(1); } } int find(int x) { if (parent[x] == x) { return x; } else { return parent[x] = find(parent[x]); } } void unite(int x, int y) { x = find(x); y = find(y); if (x == y) return; if (_rank[x] < _rank[y]) { parent[x] = y; _size[y] += _size[x]; } else { parent[y] = x; _size[x] += _size[y]; if (_rank[x] == _rank[y]) ++_rank[x]; } } bool same(int x, int y) { return find(x) == find(y); } int size(int x) { return _size[find(x)]; } }; struct Edge { int id; int from; int to; Edge(int id = -1, int from = -1, int to = -1) { this->id = id; this->from = from; this->to = to; } }; int main() { int N; cin >> N; UnionFind uf(N + 1); vector E[N + 1]; vector edges; int a, b; for (int i = 0; i < N; ++i) { cin >> a >> b; uf.unite(a, b); E[a].push_back(Edge(i, a, b)); E[b].push_back(Edge(i, b, a)); edges.push_back(Edge(i, a, b)); } int counter[N + 1]; memset(counter, 0, sizeof(counter)); for (Edge &e : edges) { int x = uf.find(e.from); counter[x]++; } typedef pair P; int ans[N]; memset(ans, -1, sizeof(ans)); bool checked[N + 1]; memset(checked, false, sizeof(checked)); for (int v = 1; v <= N; ++v) { if (checked[v]) continue; int e_cnt = counter[uf.find(v)]; if (e_cnt < uf.size(v)) { cout << "No" << endl; return 0; } bool visited[N + 1]; memset(visited, false, sizeof(visited)); stack

stk; stk.push(P(v, -1)); int root = -1; int last_eid = -1; while (not stk.empty() && root == -1) { P p = stk.top(); int u = p.first; int parent = p.second; stk.pop(); visited[u] = true; for (Edge &e : E[u]) { if (e.id == parent) continue; if (visited[e.to] && root == -1) { root = e.to; last_eid = e.id; } stk.push(P(e.to, e.id)); } } // fprintf(stderr, "v: %d, root: %d\n", v, root); stack

new_stk; memset(visited, false, sizeof(visited)); new_stk.push(P(root, -1)); while (not new_stk.empty()) { P p = new_stk.top(); int u = p.first; int parent = p.second; new_stk.pop(); if (visited[u]) continue; visited[u] = true; checked[u] = true; // fprintf(stderr, " check: %d, es: %d\n", u, (int) E[u].size()); for (Edge &e : E[u]) { if (e.id == parent) continue; if (e.id == last_eid) continue; // fprintf(stderr, " id: %d, v: %d, ans: %d\n", e.id, e.to, ans[e.id]); ans[e.id] = e.to; new_stk.push(P(e.to, e.id)); } } ans[last_eid] = root; } cout << "Yes" << endl; for (int i = 0; i < N; ++i) { cout << ans[i] << endl; } return 0; }