#include <iostream> #include <set> #include <unordered_set> #include <vector> #include <algorithm> using namespace std; const bool DBG = false; int n; int ms; int md; struct G { set<pair<int, int>> edges; }; G s, d; G read() { G g; int cnt; cin >> cnt; for (int i = 0; i < cnt; ++i) { int a, b; cin >> a >> b; g.edges.insert(pair(a, b)); g.edges.insert(pair(b, a)); } return g; } void printG(G &g) { for (auto it : g.edges) { cout << it.first << " - " << it.second << endl; } } void dfs_helper(int node, unordered_set<int> &visited, vector<int> &added, G &g) { const bool DBG = false; visited.insert(node); // Find the range for edges of the node. auto b = g.edges.lower_bound(pair(node, 0)); auto e = g.edges.upper_bound(pair(node+1, 0)); if (DBG) { cout << "+dfs " << node << endl; } for (auto it = b; it != e; ++it) { int to = it->second; if (DBG) { cout << " dfs " << to << endl; } if (visited.count(to)) continue; if (!g.edges.count(pair(1, to))) { if (DBG) { cout << " dfs add " << to << endl; } added.push_back(to); } dfs_helper(to, visited, added, g); } if (DBG) { cout << "-dfs " << node << endl; } } // Returns added edges. vector<int> dfs(G &g) { vector<int> added; unordered_set<int> visited; dfs_helper(1, visited, added, g); return added; } void print_added(vector<int> &added) { for (auto a : added) { cout << "+ 1 " << a << '\n'; } } void print_removed(vector<int> added) { reverse(added.begin(), added.end()); for (auto a : added) { cout << "- 1 " << a << '\n'; } } void print_added(vector<pair<int, int>> &added) { for (auto a : added) { cout << "+ " << a.first << ' ' << a.second << '\n'; } } void print_removed(vector<pair<int, int>> &r) { for (auto a : r) { cout << "- " << a.first << ' ' << a.second << '\n'; } } int main() { cin >> n; s = read(); d = read(); // First, create edges from 1 to everything else. auto s_added = dfs(s); if (DBG) { cout << "s_added:\n"; print_added(s_added); } auto d_added = dfs(d); if (DBG) { cout << "d_added:\n"; print_added(d_added); } vector<pair<int, int>> missing; for (auto de : d.edges) { if (de.second < de.first) continue; if (de.first == 1) continue; if (s.edges.count(de) == 0) { missing.push_back(de); } } vector<pair<int, int>> extra; for (auto se : s.edges) { if (se.second < se.first) continue; if (se.first == 1) continue; if (d.edges.count(se) == 0) { extra.push_back(se); } } cout << s_added.size() + d_added.size() + missing.size() + extra.size() << endl; print_added(s_added); print_added(missing); print_removed(extra); print_removed(d_added); 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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 | #include <iostream> #include <set> #include <unordered_set> #include <vector> #include <algorithm> using namespace std; const bool DBG = false; int n; int ms; int md; struct G { set<pair<int, int>> edges; }; G s, d; G read() { G g; int cnt; cin >> cnt; for (int i = 0; i < cnt; ++i) { int a, b; cin >> a >> b; g.edges.insert(pair(a, b)); g.edges.insert(pair(b, a)); } return g; } void printG(G &g) { for (auto it : g.edges) { cout << it.first << " - " << it.second << endl; } } void dfs_helper(int node, unordered_set<int> &visited, vector<int> &added, G &g) { const bool DBG = false; visited.insert(node); // Find the range for edges of the node. auto b = g.edges.lower_bound(pair(node, 0)); auto e = g.edges.upper_bound(pair(node+1, 0)); if (DBG) { cout << "+dfs " << node << endl; } for (auto it = b; it != e; ++it) { int to = it->second; if (DBG) { cout << " dfs " << to << endl; } if (visited.count(to)) continue; if (!g.edges.count(pair(1, to))) { if (DBG) { cout << " dfs add " << to << endl; } added.push_back(to); } dfs_helper(to, visited, added, g); } if (DBG) { cout << "-dfs " << node << endl; } } // Returns added edges. vector<int> dfs(G &g) { vector<int> added; unordered_set<int> visited; dfs_helper(1, visited, added, g); return added; } void print_added(vector<int> &added) { for (auto a : added) { cout << "+ 1 " << a << '\n'; } } void print_removed(vector<int> added) { reverse(added.begin(), added.end()); for (auto a : added) { cout << "- 1 " << a << '\n'; } } void print_added(vector<pair<int, int>> &added) { for (auto a : added) { cout << "+ " << a.first << ' ' << a.second << '\n'; } } void print_removed(vector<pair<int, int>> &r) { for (auto a : r) { cout << "- " << a.first << ' ' << a.second << '\n'; } } int main() { cin >> n; s = read(); d = read(); // First, create edges from 1 to everything else. auto s_added = dfs(s); if (DBG) { cout << "s_added:\n"; print_added(s_added); } auto d_added = dfs(d); if (DBG) { cout << "d_added:\n"; print_added(d_added); } vector<pair<int, int>> missing; for (auto de : d.edges) { if (de.second < de.first) continue; if (de.first == 1) continue; if (s.edges.count(de) == 0) { missing.push_back(de); } } vector<pair<int, int>> extra; for (auto se : s.edges) { if (se.second < se.first) continue; if (se.first == 1) continue; if (d.edges.count(se) == 0) { extra.push_back(se); } } cout << s_added.size() + d_added.size() + missing.size() + extra.size() << endl; print_added(s_added); print_added(missing); print_removed(extra); print_removed(d_added); return 0; } |