#pragma GCC optimize("O3") #pragma GCC optimize(2) #pragma GCC optimize(3) #pragma GCC optimize("Ofast") #pragma GCC optimize("inline") #pragma GCC optimize("-fgcse") #pragma GCC optimize("-fgcse-lm") #pragma GCC optimize("-fipa-sra") #pragma GCC optimize("-ftree-pre") #pragma GCC optimize("-ftree-vrp") #pragma GCC optimize("-fpeephole2") #pragma GCC optimize("-ffast-math") #pragma GCC optimize("-fsched-spec") #pragma GCC optimize("unroll-loops") #pragma GCC optimize("-falign-jumps") #pragma GCC optimize("-falign-loops") #pragma GCC optimize("-falign-labels") #pragma GCC optimize("-fdevirtualize") #pragma GCC optimize("-fcaller-saves") #pragma GCC optimize("-fcrossjumping") #pragma GCC optimize("-fthread-jumps") #pragma GCC optimize("-funroll-loops") #pragma GCC optimize("-freorder-blocks") #pragma GCC optimize("-fschedule-insns") #pragma GCC optimize("inline-functions") #pragma GCC optimize("-ftree-tail-merge") #pragma GCC optimize("-fschedule-insns2") #pragma GCC optimize("-fstrict-aliasing") #pragma GCC optimize("-falign-functions") #pragma GCC optimize("-fcse-follow-jumps") #pragma GCC optimize("-fsched-interblock") #pragma GCC optimize("-fpartial-inlining") #pragma GCC optimize("no-stack-protector") #pragma GCC optimize("-freorder-functions") #pragma GCC optimize("-findirect-inlining") #pragma GCC optimize("-fhoist-adjacent-loads") #pragma GCC optimize("-frerun-cse-after-loop") #pragma GCC optimize("inline-small-functions") #pragma GCC optimize("-finline-small-functions") #pragma GCC optimize("-ftree-switch-conversion") #pragma GCC optimize("-foptimize-sibling-calls") #pragma GCC optimize("-fexpensive-optimizations") #pragma GCC optimize("inline-functions-called-once") #pragma GCC optimize("-fdelete-null-pointer-checks") #pragma GCC optimize("Ofast") //#pragma GCC target("avx,avx2,fma") //#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native") //#pragma GCC optimization ("unroll-loops") #include using namespace std; int uf[200005]; vector > edge; vector e[200005]; set adj[200005]; int n,a,b; int parent[200005]; int find(int x) { if(uf[x] < 0) return x; return uf[x] = find(uf[x]); } bool merge(int x,int y) { x = find(x); y = find(y); if(x==y) return false; uf[x] += uf[y]; uf[y] = x; return true; } void dfs(int now,int prev,int start) { for(auto next : e[now]) { if(next==prev) continue; if(next==start) continue; parent[next] = now; dfs(next,now,start); } } void dfs2(int now,int prev) { adj[now].insert(prev); for(auto next : e[now]) { if(next==prev) continue; dfs2(next,now); } } int main(void) { cin.tie(0); ios::sync_with_stdio(false); int n,a,b; cin >> n; for(int i=0;i> a >> b; edge.push_back(make_pair(a,b)); e[a].push_back(b); e[b].push_back(a); } memset(uf,-1,sizeof(uf)); int u = -1; int v = -1; for(int i=0;i S; vector comp; int pos = v; while(1) { comp.push_back(pos); S.insert(pos); if(pos==u) break; pos = parent[pos]; } for(auto it : comp) { for(auto next : e[it]) { if(S.find(next)!=S.end()) continue; dfs2(next,it); } } for(int i=0;i" << '\n'; } else { cout << "<-" << '\n'; } } return 0; }