#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int MAXN = 120'001;
vector<int> g[MAXN], g2[MAXN];
int tin[MAXN], tout[MAXN], s[MAXN], e[MAXN], par[MAXN], col[MAXN], timer;
bool ok;
void dfs(int u, int p = -1) {
tin[u] = timer++;
par[u] = p;
for (int v : g[u]) {
if (v != p) dfs(v, u);
}
tout[u] = timer++;
}
void dfs2(int u) {
col[u] = 1;
for (int v : g2[u]) {
if (col[v] == 0) dfs2(v);
else if (col[v] == 1) ok = false;
}
col[u] = 2;
}
bool is_ancestor(int u, int v) {
return tin[u] <= tin[v] && tout[v] <= tout[u];
}
void solve() {
int n; cin >> n;
ok = true;
fill(s, s+n+1, 0);
fill(e, e+n+1, 0);
fill(col, col+n+1, 0);
timer = 1;
for (int i = 1; i <= n; i++) {
g[i].clear();
g2[i].clear();
}
for (int i = 0; i < n-1; i++) {
int u, v; cin >> u >> v;
g[u].emplace_back(v);
g[v].emplace_back(u);
}
dfs(1);
int m; cin >> m;
vector<pair<int, int>> edges(m+1);
for (int i = 1; i <= m; i++) {
cin >> edges[i].first >> edges[i].second;
auto [u, v] = edges[i];
s[u] = e[v] = i;
}
auto nxt = [&](int u, int v) {
if (u == v) return -1;
if (is_ancestor(u, v)) {
for (int i : g[u]) {
if (par[u] != i && is_ancestor(i, v)) {
return i;
}
}
} else {
return par[u];
}
};
for (int i = 1; i <= m; i++) {
auto [u, v] = edges[i];
while (u != -1) {
if (e[u] && e[u] != i) {
g2[i].emplace_back(e[u]);
}
u = nxt(u, v);
}
}
for (int i = 1; i <= m; i++) {
if (col[i] == 0) dfs2(i);
}
cout << (ok?"Yes\n":"No\n");
}
int main() {
ios::sync_with_stdio(0); cin.tie(0);
int t; cin >> t;
while (t--) {
solve();
}
return 0;
}
Compilation message
jail.cpp: In lambda function:
jail.cpp:70:5: warning: control reaches end of non-void function [-Wreturn-type]
70 | };
| ^
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
8540 KB |
Output is correct |
2 |
Correct |
2 ms |
8540 KB |
Output is correct |
3 |
Correct |
1 ms |
8540 KB |
Output is correct |
4 |
Incorrect |
7 ms |
9048 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
8540 KB |
Output is correct |
2 |
Correct |
1 ms |
8540 KB |
Output is correct |
3 |
Incorrect |
2 ms |
8796 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
8540 KB |
Output is correct |
2 |
Correct |
1 ms |
8540 KB |
Output is correct |
3 |
Incorrect |
2 ms |
8796 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
8540 KB |
Output is correct |
2 |
Correct |
1 ms |
8540 KB |
Output is correct |
3 |
Incorrect |
2 ms |
8796 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
8540 KB |
Output is correct |
2 |
Correct |
1 ms |
8540 KB |
Output is correct |
3 |
Incorrect |
2 ms |
8796 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
8536 KB |
Output is correct |
2 |
Correct |
1 ms |
8536 KB |
Output is correct |
3 |
Correct |
1 ms |
8540 KB |
Output is correct |
4 |
Correct |
1 ms |
8540 KB |
Output is correct |
5 |
Incorrect |
4 ms |
8796 KB |
Output isn't correct |
6 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
8540 KB |
Output is correct |
2 |
Correct |
2 ms |
8540 KB |
Output is correct |
3 |
Correct |
1 ms |
8540 KB |
Output is correct |
4 |
Incorrect |
7 ms |
9048 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |