#include <bits/stdc++.h> using namespace std; #define st first #define nd second #define shandom_ruffle random_shuffle const int MAXN = 30005; vector<vector<int>> g1, g2; set<pair<int, int>> e1, e2; vector<int> vis; int n; void scan_graph(vector<vector<int>> &g, set<pair<int, int>> &e) { int m; scanf("%d", &m); for (int i=0; i<m; i++) { int a, b; scanf("%d%d", &a, &b); g[a].push_back(b); g[b].push_back(a); e.insert({min(a, b), max(a, b)}); } } vector<pair<int, int>> links, unlinks; void link_op(int a, int b) { links.push_back({min(a, b), max(a, b)}); } void make_tree(const vector<vector<int>> &g, int x) { bool has_link = (x == 1); vis[x] = 1; for (int a : g[x]) { if (a == 1) has_link = true; } if (!has_link) link_op(x, 1); for (int a : g[x]) { if (vis[a]) continue; make_tree(g, a); } } void add_edges(set<pair<int, int>> &my_e, set<pair<int, int>> &opp_e) { for (auto &next : opp_e) { if (my_e.find(next) != my_e.end()) continue; if (next.st == 1 || next.nd == 1) continue; link_op(next.st, next.nd); } } int main() { scanf("%d", &n); g1.resize(n+5); g2.resize(n+5); scan_graph(g1, e1); scan_graph(g2, e2); vis.resize(n+5); make_tree(g1, 1); add_edges(e1, e2); // reverse the ops links.swap(unlinks); vis.clear(); vis.resize(n+5); make_tree(g2, 1); add_edges(e2, e1); links.swap(unlinks); printf("%d\n", (int)(links.size() + unlinks.size())); for (auto p : links) printf("+ %d %d\n", p.st, p.nd); for (int i=unlinks.size()-1; i>=0; i--) { printf("- %d %d\n", unlinks[i].st, unlinks[i].nd); } 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 | #include <bits/stdc++.h> using namespace std; #define st first #define nd second #define shandom_ruffle random_shuffle const int MAXN = 30005; vector<vector<int>> g1, g2; set<pair<int, int>> e1, e2; vector<int> vis; int n; void scan_graph(vector<vector<int>> &g, set<pair<int, int>> &e) { int m; scanf("%d", &m); for (int i=0; i<m; i++) { int a, b; scanf("%d%d", &a, &b); g[a].push_back(b); g[b].push_back(a); e.insert({min(a, b), max(a, b)}); } } vector<pair<int, int>> links, unlinks; void link_op(int a, int b) { links.push_back({min(a, b), max(a, b)}); } void make_tree(const vector<vector<int>> &g, int x) { bool has_link = (x == 1); vis[x] = 1; for (int a : g[x]) { if (a == 1) has_link = true; } if (!has_link) link_op(x, 1); for (int a : g[x]) { if (vis[a]) continue; make_tree(g, a); } } void add_edges(set<pair<int, int>> &my_e, set<pair<int, int>> &opp_e) { for (auto &next : opp_e) { if (my_e.find(next) != my_e.end()) continue; if (next.st == 1 || next.nd == 1) continue; link_op(next.st, next.nd); } } int main() { scanf("%d", &n); g1.resize(n+5); g2.resize(n+5); scan_graph(g1, e1); scan_graph(g2, e2); vis.resize(n+5); make_tree(g1, 1); add_edges(e1, e2); // reverse the ops links.swap(unlinks); vis.clear(); vis.resize(n+5); make_tree(g2, 1); add_edges(e2, e1); links.swap(unlinks); printf("%d\n", (int)(links.size() + unlinks.size())); for (auto p : links) printf("+ %d %d\n", p.st, p.nd); for (int i=unlinks.size()-1; i>=0; i--) { printf("- %d %d\n", unlinks[i].st, unlinks[i].nd); } return 0; } |