#include <bits/stdc++.h> using namespace std; vector<int> g[30001]; set<pair<int, int>> edges; vector<pair<bool, pair<int, int>>> ans; int n, m; int a, b; bool vis[30001]; void dfs1(int v){ vis[v] = true; if(v > 1 && !edges.count({1, v})){ ans.push_back({true, {1, v}}); edges.insert({1, v}); } for(auto u : g[v]){ if(!vis[u]){ dfs1(u); } } } int main(){ ios_base::sync_with_stdio(false); cin.tie(0); cin >> n >> m; for(int i = 0; i < m; i++){ cin >> a >> b; if(a > b) swap(a, b); g[a].push_back(b); g[b].push_back(a); edges.insert({a, b}); } dfs1(1); cin >> m; for(int i = 0; i < m; i++){ cin >> a >> b; if(a > b) swap(a, b); if(edges.count({a, b})){ edges.erase({a, b}); } else{ ans.push_back({true, {a, b}}); } } for(auto e : edges){ ans.push_back({false, e}); } cout << ans.size() << "\n"; for(auto e : ans){ if(e.first){ cout << "+ " << e.second.first << " " << e.second.second << "\n"; } else{ cout << "- " << e.second.first << " " << e.second.second << "\n"; } } }
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 | #include <bits/stdc++.h> using namespace std; vector<int> g[30001]; set<pair<int, int>> edges; vector<pair<bool, pair<int, int>>> ans; int n, m; int a, b; bool vis[30001]; void dfs1(int v){ vis[v] = true; if(v > 1 && !edges.count({1, v})){ ans.push_back({true, {1, v}}); edges.insert({1, v}); } for(auto u : g[v]){ if(!vis[u]){ dfs1(u); } } } int main(){ ios_base::sync_with_stdio(false); cin.tie(0); cin >> n >> m; for(int i = 0; i < m; i++){ cin >> a >> b; if(a > b) swap(a, b); g[a].push_back(b); g[b].push_back(a); edges.insert({a, b}); } dfs1(1); cin >> m; for(int i = 0; i < m; i++){ cin >> a >> b; if(a > b) swap(a, b); if(edges.count({a, b})){ edges.erase({a, b}); } else{ ans.push_back({true, {a, b}}); } } for(auto e : edges){ ans.push_back({false, e}); } cout << ans.size() << "\n"; for(auto e : ans){ if(e.first){ cout << "+ " << e.second.first << " " << e.second.second << "\n"; } else{ cout << "- " << e.second.first << " " << e.second.second << "\n"; } } } |