#include <bits/stdc++.h> using namespace std; const int MAXN = 3e5 + 7; int rep[MAXN]; set<int> g[MAXN]; int is[MAXN]; int parent[MAXN]; int n, q; int Find(int a){ if(a == rep[a]){ return a; } rep[a] = Find(rep[a]); return rep[a]; } vector<pair<int, int>> aktEdges; void dfs1(int v, int p, int source){ rep[v] = v; for(auto u : g[v]){ if(u != p){ if(u != source && v != source){ aktEdges.push_back({u, v}); dfs1(u, v, source); } } } } void usun(int v){ aktEdges.clear(); dfs1(v, v, v); for(auto ele : aktEdges){ rep[Find(ele.first)] = Find(ele.second); } is[v] = 0; for(auto ele : g[v]){ g[ele].erase(v); } g[v].clear(); } void query(int v){ if(is[v]){ cout << "1"; }else if(g[v].size() > 0){ cout << "?"; }else{ cout << "0"; } } void dfs2(int v, int p){ parent[v] = p; for(auto u : g[v]){ if(u != p){ dfs2(u, v); } } } void Union(int a, int b){ int repa = Find(a); int repb = Find(b); if(repa != repb){ g[a].insert(b); g[b].insert(a); rep[repa] = repb; return; } dfs2(a, a); vector<int> cycle; while(parent[b] != b){ cycle.push_back(b); b = parent[b]; } cycle.push_back(a); for(auto u : cycle){ is[u] = true; for(auto s : g[u]){ g[s].erase(u); } g[u].clear(); } } int main(){ ios_base::sync_with_stdio(0); cin.tie(NULL); cout.tie(NULL); cin >> n >> q; for(int i = 1; i <= n; i++){ rep[i] = i; } while(q--){ char c; cin >> c; if(c == '-'){ int v; cin >> v; usun(v); }else if(c == '?'){ int v; cin >> v; query(v); }else{ int a, b; cin >> a >> b; Union(a, b); } } cout << '\n'; return 0; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 | #include <bits/stdc++.h> using namespace std; const int MAXN = 3e5 + 7; int rep[MAXN]; set<int> g[MAXN]; int is[MAXN]; int parent[MAXN]; int n, q; int Find(int a){ if(a == rep[a]){ return a; } rep[a] = Find(rep[a]); return rep[a]; } vector<pair<int, int>> aktEdges; void dfs1(int v, int p, int source){ rep[v] = v; for(auto u : g[v]){ if(u != p){ if(u != source && v != source){ aktEdges.push_back({u, v}); dfs1(u, v, source); } } } } void usun(int v){ aktEdges.clear(); dfs1(v, v, v); for(auto ele : aktEdges){ rep[Find(ele.first)] = Find(ele.second); } is[v] = 0; for(auto ele : g[v]){ g[ele].erase(v); } g[v].clear(); } void query(int v){ if(is[v]){ cout << "1"; }else if(g[v].size() > 0){ cout << "?"; }else{ cout << "0"; } } void dfs2(int v, int p){ parent[v] = p; for(auto u : g[v]){ if(u != p){ dfs2(u, v); } } } void Union(int a, int b){ int repa = Find(a); int repb = Find(b); if(repa != repb){ g[a].insert(b); g[b].insert(a); rep[repa] = repb; return; } dfs2(a, a); vector<int> cycle; while(parent[b] != b){ cycle.push_back(b); b = parent[b]; } cycle.push_back(a); for(auto u : cycle){ is[u] = true; for(auto s : g[u]){ g[s].erase(u); } g[u].clear(); } } int main(){ ios_base::sync_with_stdio(0); cin.tie(NULL); cout.tie(NULL); cin >> n >> q; for(int i = 1; i <= n; i++){ rep[i] = i; } while(q--){ char c; cin >> c; if(c == '-'){ int v; cin >> v; usun(v); }else if(c == '?'){ int v; cin >> v; query(v); }else{ int a, b; cin >> a >> b; Union(a, b); } } cout << '\n'; return 0; } |