#include <iostream>
#include <set>
#include <vector>
#include <sstream>
#define nl '\n'
using namespace std;
int n, op_count = 0;
vector<string> ops;
vector<set<int>> G, Gd;
vector<int> vis, vis2;
void addEdge(int u, int v){
op_count++;
stringstream ss;
ss<<"+ "<<u<<' '<<v<<nl;
ops.push_back(ss.str());
G[u].insert(v);
G[v].insert(u);
}
void delEdge(int u, int v){
op_count++;
stringstream ss;
ss<<"- "<<u<<' '<<v<<nl;
ops.push_back(ss.str());
G[u].erase(v);
G[v].erase(u);
}
void dfs(int v){
vis[v] = 1;
for(auto i:G[v]){
if(vis[i]) continue;
if(!G[1].count(i)){ addEdge(1, i); }
dfs(i);
}
}
void dfs2(int v){
vis2[v] = 1;
for(auto i:Gd[v]){
if(vis2[i]) continue;
dfs2(i);
if(!Gd[1].count(i)){ delEdge(1, i); }
}
}
int main()
{
cin.tie(0)->sync_with_stdio(0);
cin>>n;
vis.resize(n+1, 0);
vis2.resize(n+1, 0);
G.resize(n+1, {});
Gd.resize(n+1, {});
int m1, m2;
cin>>m1;
while(m1--){
int u, v;
cin>>u>>v;
G[u].insert(v);
G[v].insert(u);
}
cin>>m2;
while(m2--){
int u, v;
cin>>u>>v;
Gd[u].insert(v);
Gd[v].insert(u);
}
dfs(1);
for(int i=1; i<=n; i++){
for(auto v : Gd[i]){
if(!G[i].count(v)){ addEdge(i, v); }
}
}
for(int i=2; i<=n; i++){
vector<int> to_del;
for(auto v : G[i]){
if(!Gd[i].count(v) && v != 1){ to_del.push_back(v); }
}
for(auto v: to_del){
delEdge(i, v);
}
}
dfs2(1);
cout<<op_count<<nl;
for(auto i:ops){
cout<<i;
}
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 | #include <iostream> #include <set> #include <vector> #include <sstream> #define nl '\n' using namespace std; int n, op_count = 0; vector<string> ops; vector<set<int>> G, Gd; vector<int> vis, vis2; void addEdge(int u, int v){ op_count++; stringstream ss; ss<<"+ "<<u<<' '<<v<<nl; ops.push_back(ss.str()); G[u].insert(v); G[v].insert(u); } void delEdge(int u, int v){ op_count++; stringstream ss; ss<<"- "<<u<<' '<<v<<nl; ops.push_back(ss.str()); G[u].erase(v); G[v].erase(u); } void dfs(int v){ vis[v] = 1; for(auto i:G[v]){ if(vis[i]) continue; if(!G[1].count(i)){ addEdge(1, i); } dfs(i); } } void dfs2(int v){ vis2[v] = 1; for(auto i:Gd[v]){ if(vis2[i]) continue; dfs2(i); if(!Gd[1].count(i)){ delEdge(1, i); } } } int main() { cin.tie(0)->sync_with_stdio(0); cin>>n; vis.resize(n+1, 0); vis2.resize(n+1, 0); G.resize(n+1, {}); Gd.resize(n+1, {}); int m1, m2; cin>>m1; while(m1--){ int u, v; cin>>u>>v; G[u].insert(v); G[v].insert(u); } cin>>m2; while(m2--){ int u, v; cin>>u>>v; Gd[u].insert(v); Gd[v].insert(u); } dfs(1); for(int i=1; i<=n; i++){ for(auto v : Gd[i]){ if(!G[i].count(v)){ addEdge(i, v); } } } for(int i=2; i<=n; i++){ vector<int> to_del; for(auto v : G[i]){ if(!Gd[i].count(v) && v != 1){ to_del.push_back(v); } } for(auto v: to_del){ delEdge(i, v); } } dfs2(1); cout<<op_count<<nl; for(auto i:ops){ cout<<i; } return 0; } |
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