#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define F first
#define S second
#define pb push_back
#define endl "\n"
#define all(x) x.begin(), x.end()
const int M = 200007;
const ll inf = 1e9;
const ll INF = 1e18;
const ll mod = 1e9 + 7;
const double pi = acos(-1);
const double eps = 1e-6;
const int dx[] = {0, -1, 0, 1}, dy[] = {1, 0, -1, 0};
const int block = 320;
vector <int> adj[M], to[M];
int n, m, s[M], t[M], dep[M], anc[M][30], in[M], st[M], out[M], timer;
bool con(int i, int j){
return st[i] <= st[j] && out[i] >= out[j];
}
int lca(int x, int y){
if(x == y) return x;
if(dep[x] > dep[y]) swap(x, y);
for(int i = 18; i >= 0; --i) if(dep[anc[y][i]] >= dep[x]) y = anc[y][i];
if(x == y) return x;
for(int i = 18; i >= 0; --i) if(anc[x][i] != anc[y][i]){
x = anc[x][i];
y = anc[y][i];
}
return anc[x][0];
}
bool check(int i, int j){
int x = lca(s[i], t[i]);
int y = lca(s[j], t[j]);
if((x != s[i] && x != t[i]) && (y != s[j] && y != t[j])){
if(!con(s[i], s[j]) && !con(t[i], s[j]) && con(lca(s[i], t[i]), s[j])) return 0;
if(!con(s[j], t[i]) && !con(t[j], t[i]) && con(lca(s[j], t[j]), t[i])) return 0;
}
else{
if(con(s[i], s[j]) && con(s[i], t[j]) && !con(t[i], s[j]) && !con(t[i], t[j])) return 0;
if(con(t[i], s[j]) && con(t[i], t[j]) && !con(s[i], s[j]) && !con(s[i], t[j])) return 0;
if(con(s[j], s[i]) && con(s[j], t[i]) && !con(t[j], s[i]) && !con(t[j], t[i])) return 0;
if(con(t[j], s[i]) && con(t[j], t[i]) && !con(s[j], s[i]) && !con(s[j], t[i])) return 0;
}
return 1;
}
void dfs(int node, int par){
st[node] = ++timer;
for(auto i : adj[node]) if(i != par){
dep[i] = dep[node] + 1;
anc[i][0] = node;
dfs(i, node);
}
out[node] = ++timer;
return;
}
int main(){
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int q;
cin >> q;
while(q--){
cin >> n;
for(int i = 1; i < n; ++i){
int x, y;
cin >> x >> y;
adj[x].pb(y);
adj[y].pb(x);
}
dep[1] = 1;
dfs(1, 0);
for(int j = 1; j < 19; ++j)
for(int i = 1; i <= n; ++i)
anc[i][j] = anc[anc[i][j - 1]][j - 1];
cin >> m;
for(int i = 1; i <= m; ++i) cin >> s[i] >> t[i];
for(int i = 1; i <= m; ++i){
for(int j = 1; j <= m; ++j){
if(i != j && !check(i, j)) to[j].pb(i), ++in[i];
}
}
queue <int> q;
for(int i = 1; i <= m; ++i) if(!in[i]) q.push(i);
int cnt = 0;
while(!q.empty()){
int node = q.front();
q.pop();
++cnt;
for(auto i : to[node]){
--in[i];
if(!in[i]) q.push(i);
}
}
cout << (cnt != m ? "No\n" : "Yes\n");
for(int i = 1; i <= n; ++i){
adj[i].clear();
to[i].clear();
in[i] = 0;
}
}
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
9684 KB |
Output is correct |
2 |
Correct |
5 ms |
9696 KB |
Output is correct |
3 |
Incorrect |
6 ms |
9684 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
9684 KB |
Output is correct |
2 |
Incorrect |
7 ms |
9684 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
9684 KB |
Output is correct |
2 |
Incorrect |
7 ms |
9684 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
9684 KB |
Output is correct |
2 |
Incorrect |
7 ms |
9684 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
9684 KB |
Output is correct |
2 |
Incorrect |
7 ms |
9684 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
9684 KB |
Output is correct |
2 |
Correct |
7 ms |
9684 KB |
Output is correct |
3 |
Correct |
5 ms |
9684 KB |
Output is correct |
4 |
Incorrect |
5 ms |
9684 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
9684 KB |
Output is correct |
2 |
Correct |
5 ms |
9696 KB |
Output is correct |
3 |
Incorrect |
6 ms |
9684 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |