// Lotfan komak
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define all(x) x.begin(), x.end()
#define fi first
#define se second
#define pb push_back
const int maxn5 = 2e5 + 10;
const int lg = 20;
const int mod = 1e9 + 7;
vector <int> adj[maxn5], ed[maxn5];
bool cy = false;
int mark[maxn5], par[lg + 1][maxn5];
int s[maxn5], t[maxn5], ti = 0, st[maxn5], ft[maxn5];
int h[maxn5];
void dfs_lca(int v){
st[v] = ++ti;
for(int i = 1; i < lg && par[i - 1][v] != -1; i++)
par[i][v] = par[i - 1][par[i - 1][v]];
for(auto u : adj[v]) if(u != par[0][v]){
par[0][u] = v;
h[u] = h[v] + 1;
dfs_lca(u);
}
ft[v] = ti;
}
void dfs(int v){
mark[v] = 1;
for(auto u : ed[v]){
if(mark[u] == 0)
dfs(u);
else if(mark[u] == 1)
cy = true;
}
mark[v] = 2;
}
inline int lca(int a, int b){
if(h[a] < h[b])
swap(a, b);
int d = h[a] - h[b];
for(int i = 0; i < lg; i++) if((d >> i)&1)
a = par[i][a];
if(a == b)
return a;
for(int i = lg - 1; i >= 0; i--) if(par[i][a] != par[i][b]){
a = par[i][a];
b = par[i][b];
}
return par[0][a];
}
inline bool isinpath(int a, int b, int c){
int x = lca(a, b);
if(h[c] < h[x])
return false;
if(st[c] <= st[a] && ft[c] >= ft[a])
return true;
swap(a, b);
return (st[c] <= st[a] && ft[c] >= ft[a]);
}
int main(){
ios_base::sync_with_stdio(false); cin.tie(0);
int tt; cin >> tt;
while(tt--){
int n; cin >> n;
for(int i = 0; i < n; i++){
adj[i].clear();
for(int j = 0; j < lg; j++)
par[j][i] = -1;
}
for(int i = 0; i < n - 1; i++){
int a, b; cin >> a >> b;
a--; b--;
adj[a].pb(b);
adj[b].pb(a);
}
h[0] = 0;
ti = 0;
dfs_lca(0);
int m; cin >> m;
cy = false;
for(int i = 0; i < m; i++){
ed[i].clear();
mark[i] = 0;
}
for(int i = 0; i < m; i++){
cin >> s[i] >> t[i];
s[i]--; t[i]--;
for(int j = 0; j < i; j++){
if(isinpath(s[i], t[i], s[j]) && isinpath(s[i], t[i], t[j])){
cy = true;
break;
}
if(isinpath(s[j], t[j], s[i]) && isinpath(s[j], t[j], t[i])){
cy = true;
break;
}
if(isinpath(s[i], t[i], s[j])){
if(st[s[i]] <= st[t[j]] && ft[s[i]] >= ft[t[j]]){
cy = true;
break;
}
ed[j].pb(i);
continue;
}
if(isinpath(s[i], t[i], t[j])){
if(st[t[i]] <= st[s[j]] && ft[t[i]] >= ft[s[j]]){
cy = true;
break;
}
ed[i].pb(j);
continue;
}
swap(i, j);
if(isinpath(s[i], t[i], s[j])){
if(st[s[i]] <= st[t[j]] && ft[s[i]] >= ft[t[j]]){
cy = true;
break;
}
ed[j].pb(i);
swap(i, j);
continue;
}
if(isinpath(s[i], t[i], t[j])){
if(st[t[i]] <= st[s[j]] && ft[t[i]] >= ft[s[j]]){
cy = true;
break;
}
ed[i].pb(j);
swap(i, j);
continue;
}
swap(i, j);
}
}
if(cy){
cout << "No\n";
continue;
}
else{
cout << "Yes\n";
continue;
}
for(int i = 0; i < m; i++) if(!mark[i])
dfs(i);
cout << (cy ? "No\n" : "Yes\n");
}
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
9812 KB |
Output is correct |
2 |
Correct |
5 ms |
9812 KB |
Output is correct |
3 |
Correct |
6 ms |
9812 KB |
Output is correct |
4 |
Incorrect |
16 ms |
9812 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
9812 KB |
Output is correct |
2 |
Correct |
6 ms |
9812 KB |
Output is correct |
3 |
Incorrect |
6 ms |
9812 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
9812 KB |
Output is correct |
2 |
Correct |
6 ms |
9812 KB |
Output is correct |
3 |
Incorrect |
6 ms |
9812 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
9812 KB |
Output is correct |
2 |
Correct |
6 ms |
9812 KB |
Output is correct |
3 |
Incorrect |
6 ms |
9812 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
9812 KB |
Output is correct |
2 |
Correct |
6 ms |
9812 KB |
Output is correct |
3 |
Incorrect |
6 ms |
9812 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
9836 KB |
Output is correct |
2 |
Incorrect |
6 ms |
9812 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
9812 KB |
Output is correct |
2 |
Correct |
5 ms |
9812 KB |
Output is correct |
3 |
Correct |
6 ms |
9812 KB |
Output is correct |
4 |
Incorrect |
16 ms |
9812 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |