#include <bits/stdc++.h>
#define f first
#define s second
using namespace std;
const int N = 120069;
const int K = 20;
int n, m, a[N], b[N];
int tin[N], tout[N], timer, up[N][K], dep[N], is, vis[N];
vector<int> g[N];
vector<int> gg[N];
bool anc(int a, int b) {
return tin[a] <= tin[b] && tout[a] >= tout[b];
}
int lca(int a, int b) {
if (anc(a, b))
return a;
else if (anc(b, a))
return b;
for (int i = K - 1;i >= 0;i--) {
if (!anc(up[a][i], b) && up[a][i] > 0)
a = up[a][i];
}
return up[a][0];
}
void dfs(int v, int p) {
up[v][0] = p;
tin[v] = ++timer;
for (int i = 1;i < K;i++)
up[v][i] = up[up[v][i - 1]][i - 1];
for (auto u : g[v]) {
if (u == p)
continue;
dep[u] = dep[v] + 1;
dfs(u, v);
}
tout[v] = ++timer;
}
void dfs(int v) {
if (vis[v]) {
is += (vis[v] == 1);
return;
}
vis[v] = 1;
for (auto u : gg[v])
dfs(u);
vis[v] = 2;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
int tt;
cin >> tt;
while (tt--) {
cin >> n;
timer = is = 0;
for (int i = 1;i <= n;i++) {
g[i].clear();
gg[i].clear();
vis[i] = 0;
for (int j = 0;j < K;j++)
up[i][j] = 0;
}
for (int i = 1;i <= n - 1;i++) {
int a, b;
cin >> a >> b;
g[a].push_back(b);
g[b].push_back(a);
}
cin >> m;
for (int i = 1;i <= m;i++)
cin >> a[i] >> b[i];
dfs(1, 0);
for (int i = 1;i <= m;i++) {
for (int j = 1;j <= m;j++) {
if (i == j)
continue;
// da li je i u j
//ako b[i] pripada onda j mora zavrsim pre i
int dis = dep[a[j]] + dep[b[j]] - 2 * dep[lca(a[j], b[j])];
int dd1 = dep[a[j]] + dep[b[i]] - 2 * dep[lca(a[j], b[i])];
int dd2 = dep[b[j]] + dep[b[i]] - 2 * dep[lca(b[j], b[i])];
if (dis == dd1 + dd2)
gg[j].push_back(i);
}
}
for (int i = 1;i <= n;i++) {
if (!vis[i]) {
dfs(i);
}
}
if (is)
cout << "No\n";
else
cout << "Yes\n";
}
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
10844 KB |
Output is correct |
2 |
Correct |
2 ms |
10844 KB |
Output is correct |
3 |
Correct |
2 ms |
10908 KB |
Output is correct |
4 |
Incorrect |
8 ms |
11100 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
10844 KB |
Output is correct |
2 |
Correct |
1 ms |
10844 KB |
Output is correct |
3 |
Incorrect |
2 ms |
10844 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
10844 KB |
Output is correct |
2 |
Correct |
1 ms |
10844 KB |
Output is correct |
3 |
Incorrect |
2 ms |
10844 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
10844 KB |
Output is correct |
2 |
Correct |
1 ms |
10844 KB |
Output is correct |
3 |
Incorrect |
2 ms |
10844 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
10844 KB |
Output is correct |
2 |
Correct |
1 ms |
10844 KB |
Output is correct |
3 |
Incorrect |
2 ms |
10844 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
10844 KB |
Output is correct |
2 |
Correct |
2 ms |
10844 KB |
Output is correct |
3 |
Correct |
1 ms |
10844 KB |
Output is correct |
4 |
Correct |
1 ms |
10844 KB |
Output is correct |
5 |
Incorrect |
5 ms |
10844 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
10844 KB |
Output is correct |
2 |
Correct |
2 ms |
10844 KB |
Output is correct |
3 |
Correct |
2 ms |
10908 KB |
Output is correct |
4 |
Incorrect |
8 ms |
11100 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |