#include <bits/stdc++.h>
#define MAX 500005
#define MOD (ll)(1e9+7)
#define INF (ll)(1e18)
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
int n, m, tt;
int parent[120005][25];
int s[120005], t[120005], dep[120005];
vector<int> graph[120005];
int main()
{
ios::sync_with_stdio(false);
cin.tie(NULL);
cin >> tt;
while(tt--) {
cin >> n;
for(int i = 1; i <= n; ++i) graph[i].clear();
for(int i = 1; i <= n; ++i) for(int j = 0; j <= 20; ++j) parent[i][j] = 0;
for(int i = 1; i <= n - 1; ++i) {
int a, b; cin >> a >> b;
graph[a].push_back(b);
graph[b].push_back(a);
}
cin >> m;
for(int i = 1; i <= m; ++i) cin >> s[i] >> t[i];
auto dfs = [&](auto&& self, int node, int par) -> void {
parent[node][0] = par; dep[node] = dep[par] + 1;
for(auto v : graph[node]) if(v != par) self(self, v, node);
};
dfs(dfs, 1, 0);
for(int j = 1; j < 20; ++j) for(int i = 1; i <= n; ++i) parent[i][j] = parent[parent[i][j - 1]][j - 1];
auto LCA = [&](int u, int v) -> int {
if(dep[u] < dep[v]) swap(u, v);
int diff = dep[u] - dep[v], j = 0;
while(diff) {
if(diff & 1) u = parent[u][j];
diff >>= 1; ++j;
}
if(u == v) return u;
for(int i = 19; i >= 0; --i) {
if(parent[u][i] != parent[v][i]) {
u = parent[u][i];
v = parent[v][i];
}
}
return parent[u][0];
};
auto path = [](int s, int t, int n) -> bool {
while(s != t) {
if(s == n) return false;
s = parent[s][0];
}
return s == n;
};
auto chk = [&](int s1, int t1, int s2, int t2) -> bool {
int p1 = LCA(s1, t1), p2 = LCA(s2, t2);
if(!path(s1, p1, s2) || !path(t1, p1, s2)) return false;
if(!path(s2, p2, t1) || !path(t2, p2, t1)) return false;
return true;
};
if(chk(s[1], t[1], s[2], t[2]) || chk(s[2], t[2], s[1], t[1])) cout << "YES\n";
else cout << "NO\n";
}
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
2 ms |
3028 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
3156 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
3156 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
3156 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
3156 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
3156 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
2 ms |
3028 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |