This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
const int maxn = 120005, maxN = 480005, lgn = 17, INF = 1e6;
int n, m;
vector<int> ADJ[maxn], adj[maxn];
pair<int,int> a[maxn];
int sz[maxn], fa[maxn], d[maxn], newid[maxn], lim[maxn], cnter = 0;
bool cmp(int &x, int &y) {
return sz[x] > sz[y];
}
void dfs1(int u) {
sz[u] = 1;
for (int v:ADJ[u]) {
ADJ[v].erase(find(ADJ[v].begin(), ADJ[v].end(), u));
dfs1(v);
sz[u] += sz[v];
}
sort(ADJ[u].begin(), ADJ[u].end(), cmp);
}
void dfs2(int u) {
cnter++;
newid[u] = cnter;
for (int v:ADJ[u]) {
d[cnter+1] = d[newid[u]] + 1;
fa[cnter+1] = newid[u];
dfs2(v);
}
lim[newid[u]] = cnter;
}
int skip[maxn];
void dfs3(int u) {
for (int v:adj[u]) {
if (v == adj[u][0]) skip[v] = skip[u];
else skip[v] = v;
dfs3(v);
}
}
vector<pair<int,int>> path;
void PATH(int u, int v) {
// bool TEST = (u == a[3].first && v == a[3].second);
path.clear();
if (d[u] > d[v]) swap(u, v);
path = {{skip[u], u}};
u = skip[u];
while (u>v || v>lim[u]) {
u = fa[u];
path.push_back({skip[u], u});
u = skip[u];
}
auto [l, r] = path.back();
while (l<r) {
int mid = (l+r+1)/2;
if (mid<=v && v<=lim[mid]) l = mid;
else r = mid-1;
}
path.back().first = u = l;
path.push_back({skip[v], v});
v = skip[v];
while (d[fa[v]] > d[u]) {
v = fa[v];
path.push_back({skip[v], v});
v = skip[v];
}
path.back().first += d[u] - d[v] + 1;
// if (TEST) {
// cout << "PATH\n";
// for (auto [L, R]:path) cout << L << " " << R << endl;
// }
}
set<pair<int,int>> chain[maxn];
set<int> seg[maxN];
void build(int id, int l, int r) {
seg[id].clear();
if (l==r) return;
int mid = (l+r)/2;
build(id*2, l, mid); build(id*2+1, mid+1, r);
}
void update(int id, int l, int r, int &findl, int &findr, int &val, bool psh) {
if (r<findl || findr<l) return;
if (findl<=l && r<=findr) {
if (psh) seg[id].insert(val);
else seg[id].erase(val);
// if (val == 3) cout << l << " " << r << " " << psh << endl;
return;
}
int mid = (l+r)/2;
update(id*2, l, mid, findl, findr, val, psh);
update(id*2+1, mid+1, r, findl, findr, val, psh);
}
vector<int> nxt;
void qry(int id, int l, int r, int &target) {
if (r<target || target<l) return;
for (int i:seg[id]) nxt.push_back(i);
if (l==r) return;
int mid = (l+r)/2;
qry(id*2, l, mid, target); qry(id*2+1, mid+1, r, target);
}
void UPDATE(int l, int r, int val, int psh) {
// if (val == 3) cout << "test " << l << " " << r << " " << psh << endl;
if (l==skip[l]) {
if (psh) chain[l].insert({r, val});
else chain[l].erase({r, val});
// cout << l << " " << r << " " << val << " " << psh << endl;
} else update(1, 1, n, l, r, val, psh);
}
int S[maxn], vis[maxn];
bool die = false;
set<int> exist;
void dfs4(int u) {
auto [s, t] = a[u];
// cout << "start " << u << " " << s << " " << t << endl;
vis[u] = 1;
PATH(s, t);
for (auto [L, R]:path) {
int cur = L-1;
while (true) {
cur = *exist.upper_bound(cur);
if (cur > R) break;
if (cur==s) continue;
int v = S[cur];
// cout << "1 " << u << " " << v << " " << die << endl;
if (!vis[v]) dfs4(v);
else die = true;
if (die) return;
}
}
nxt.clear();
qry(1, 1, n, t);
for (int v:nxt) if (v!=u) {
// cout << "2 " << u << " " << v << " " << die << endl;
if (!vis[v]) dfs4(v);
else die = true;
if (die) return;
}
int head = skip[t];
pair<int,int> cur = {t, 0};
while (true) {
cur = *chain[head].upper_bound(cur);
if (cur.first == INF) break;
if (cur.second == u) continue;
int v = cur.second;
// cout << "3 " << u << " " << v << " " << die << endl;
if (!vis[v]) dfs4(v);
else die = true;
if (die) return;
}
PATH(s, t);
for (auto [L, R]:path) UPDATE(L, R, u, 0);
exist.erase(s);
// cout << "killed " << u << endl;
// vis[u] = 2;
}
void solve() {
cin >> n;
for (int i=1;i<=n;i++) sz[i] = 0, adj[i].clear(), ADJ[i].clear();
cnter = 0;
for (int i=1;i<=n-1;i++) {
int u, v;
cin >> u >> v;
ADJ[u].push_back(v);
ADJ[v].push_back(u);
}
fa[1] = 0, d[1] = 0;
dfs1(1); dfs2(1);
for (int i=1;i<=n;i++) for (int j:ADJ[i]) adj[newid[i]].push_back(newid[j]);
skip[1] = 1;
dfs3(1);
exist = {INF};
build(1, 1, n);
for (int i=1;i<=n;i++) chain[i] = {{INF, INF}}, S[i] = -1;
cin >> m;
for (int i=1;i<=m;i++) {
int s, t;
cin >> s >> t;
s = newid[s], t = newid[t];
a[i] = {s, t};
S[s] = i;
exist.insert(s);
PATH(s, t);
for (auto [L, R]:path) UPDATE(L, R, i, 1);
}
for (int i=1;i<=m;i++) vis[i] = 0;
die = false;
for (int i=1;i<=m;i++) if (!vis[i]) {
dfs4(i);
if (die) break;
}
if (die) cout << "No\n";
else cout << "Yes\n";
}
signed main() {
ios::sync_with_stdio(0); cin.tie(0);
int t;
cin >> t;
while (t--) solve();
}
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