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;
using ll = long long;
using pii = pair<int, int>;
struct FT{
vector<int> bit;
int n;
FT(int ns){
n = ns;
bit.resize(n + 1);
}
int get(int v){
int out = 0;
while (v > 0){
out += bit[v];
v = (v & (v + 1)) - 1;
}
return out;
}
void upd(int v, int k){
while (v <= n){
bit[v] += k;
v |= (v + 1);
}
}
};
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int q; cin>>q;
while (q--){
int n; cin>>n;
vector<int> g[n + 1];
for (int i = 1; i < n; i++){
int a, b; cin>>a>>b;
g[a].push_back(b);
g[b].push_back(a);
}
int m; cin>>m;
vector<int> s(m + 1), t(m + 1);
vector<bool> used(n + 1);
for (int i = 1; i <= m; i++){
cin>>s[i]>>t[i];
used[s[i]] = i;
}
vector<int> tin(n + 1), tout(n + 1), p(n + 1);
int lg = ceil(log2(n)) + 1;
vector<int> pw[n + 1];
for (int i = 1; i <= n; i++){
pw[i].resize(lg);
}
int timer = 0;
function<void(int, int, int)> fill = [&](int v, int pr, int k){
p[v] = k;
if (used[v]) k = v;
tin[v] = ++timer;
pw[v][0] = pr;
for (int i = 1; i < lg; i++){
pw[v][i] = pw[pw[v][i - 1]][i - 1];
}
for (int i: g[v]){
if (i == pr) continue;
fill(i, v, k);
}
tout[v] = timer;
};
fill(1, 1, 0);
auto check = [&](int x, int y){
return (tin[x] <= tin[y] && tout[x] >= tout[y]);
};
auto lca = [&](int x, int y){
if (check(x, y)) return x;
if (check(y, x)) return y;
for (int i = lg - 1; i >= 0; i--){
if (!check(pw[x][i], y)){
x = pw[x][i];
}
}
return pw[x][0];
};
vector<int> l(m + 1);
for (int i = 1; i <= m; i++){
l[i] = lca(s[i], t[i]);
}
vector<bool> ban(n + 1);
function<int(int)> get = [&](int v){
if (!v) return 0;
if (used[v] && !ban[v]){
p[v] = p[pw[v][0]];
ban[v] = true;
return v;
}
return p[v] = get(p[v]);
};
vector<int> order;
function<void(int)> dfs = [&](int v){
int x;
while (check(l[v], x = get(s[v]))){
dfs(used[x]);
}
while (check(l[v], x = get(t[v]))){
dfs(used[x]);
}
order.push_back(v);
};
FT T(n);
auto upd = [&](int i, int k){
T.upd(tin[s[i]], k);
T.upd(tout[s[i]] + 1, -k);
};
for (int i = 1; i <= m; i++){
upd(i, 1);
}
auto sum = [&](int i){
return T.get(tin[s[i]]) + T.get(tin[t[i]]) - 2 * T.get(tin[l[i]]) + (T.get(tin[l[i]]) - T.get(tin[pw[l[i]][0]]));
};
vector<pii> a;
for (int i = 1; i <= m; i++){
a.push_back({sum(i), i});
}
sort(a.begin(), a.end(), greater<pii>());
for (auto [x, i]: a){
dfs(i);
}
reverse(order.begin(), order.end());
bool out = true;
for (int i: order){
if (sum(i) > 1){
out = false;
break;
}
upd(i, -1);
}
cout<<((out == true) ? "Yes" : "No")<<"\n";
}
}
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