#include <bits/stdc++.h>
using namespace std;
#define int long long
#define FOR(i,s,e) for(int i = s; i <= (int)e; ++i)
#define DEC(i,s,e) for(int i = s; i >= (int)e; --i)
#define IAMSPEED ios_base::sync_with_stdio(false); cin.tie(0);
#ifdef LOCAL
#define db(x) cerr << #x << "=" << x << "\n"
#define db2(x, y) cerr << #x << "=" << x << " , " << #y << "=" << y << "\n"
#define db3(a,b,c) cerr<<#a<<"="<<a<<","<<#b<<"="<<b<<","<<#c<<"="<<c<<"\n"
#define dbv(v) cerr << #v << ":"; for (auto ite : v) cerr << ite << ' '; cerr <<"\n"
#define dbvp(v) cerr << #v << ":"; for (auto ite : v) cerr << "{" << ite.f << ',' << ite.s << "} "; cerr << "\n"
#define dba(a,ss,ee) cerr << #a << ":"; FOR(ite,ss,ee) cerr << a[ite] << ' '; cerr << "\n"
#define reach cerr << "LINE: " << __LINE__ << "\n";
#else
#define reach
#define db(x)
#define db2(x,y)
#define db3(a,b,c)
#define dbv(v)
#define dbvp(v)
#define dba(a,ss,ee)
#endif
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
#define pb push_back
#define eb emplace_back
#define all(x) (x).begin(), (x).end()
#define f first
#define s second
#define g0(x) get<0>(x)
#define g1(x) get<1>(x)
#define g2(x) get<2>(x)
#define g3(x) get<3>(x)
typedef pair <int, int> pi;
typedef tuple<int,int,int> ti3;
typedef tuple<int,int,int,int> ti4;
int rand(int a, int b) { return a + rng() % (b-a+1); }
const int MOD = 1e9 + 7;
const int inf = (int)1e9 + 500;
const long long oo = (long long)1e18 + 500;
template <typename T> void chmax(T& a, const T b) { a=max(a,b); }
template <typename T> void chmin(T& a, const T b) { a=min(a,b); }
const int MAXN = 120005;
int q;
vector<int> adj[MAXN];
int S[MAXN], T[MAXN];
int dep[MAXN];
int twok[MAXN][20];
int pre[MAXN], post[MAXN];
int cnt;
int lift(int x, int k) {
FOR(i,0,19){
if((1<<i)&k)x=twok[x][i];
if(x==-1)return -1;
}
return x;
}
int lca(int x, int y) {
if(dep[x]>dep[y]) {
int dd=dep[x]-dep[y];
x=lift(x,dd);
} else {
int dd=dep[y]-dep[x];
y=lift(y,dd);
}
if(x==y)return x;
DEC(i,19,0){
if(twok[x][i]!=twok[y][i]){
x=twok[x][i];
y=twok[y][i];
}
}
return twok[x][0];
}
void dfs(int x, int p, int lvl) {
pre[x]=cnt++;
dep[x]=lvl;
twok[x][0]=p;
FOR(i,1,19){
if(twok[x][i-1] == -1)continue;
twok[x][i]=twok[twok[x][i-1]][i-1];
}
for(auto v:adj[x])if(v!=p) {
dfs(v,x,lvl+1);
}
post[x]=cnt-1;
}
vector<int> V[MAXN];
bool isanc(int par, int child) {
if(pre[par]<pre[child] && post[par]>=pre[child]) return 1;
else return 0;
}
bool ispar(int par, int child) {
if(pre[par]<=pre[child] && post[par]>=pre[child]) return 1;
else return 0;
}
bool onpath(int x, int y, int node) {
db3(x,y,node);
// check if node is on path from x to y
if(ispar(y,x)) {
return (ispar(y,node) && !ispar(x,node));
}
if(ispar(x,y)) {
return (ispar(x,node) && !ispar(y,node));
}
int par=lca(x,y);
if(isanc(x,node)||isanc(y,node))return 0;
if(ispar(par,node) && (ispar(node, x) || ispar(node, y))) return 1;
else return 0;
}
int vis[MAXN];
bool dfs(int x) {
bool res=0;
int col = 0;
if(vis[x] == 2) {
return 1;
}
vis[x]=2; // active
for(auto v:V[x]){
if(vis[v] == 2) return 1;
if(vis[v] == 1) continue;
else chmax(res, dfs(v));
}
vis[x]=1;
return res;
}
void solve(){
int n; cin >> n;
memset(twok,-1,sizeof twok);
FOR(i,1,n-1) {
int a,b; cin >> a >> b;
adj[a].pb(b);
adj[b].pb(a);
}
dfs(1,-1,0);
int m; cin >> m;
FOR(i,1,m) cin >> S[i] >> T[i];
bool bad=0;
FOR(i,1,m){
FOR(j,1,m){
if(i!=j) {
// check if there's an edge between i and j
bool y1=onpath(S[i],T[i],S[j]);
bool y2=onpath(S[i],T[i],T[j]);
db2(i,j);
db2(y1,y2);
if(y1&&y2){
bad=1;
goto done;
}
if(y1) { // you must do j before i
V[j].pb(i);
}
if(y2) { // you must do j after i
V[i].pb(j);
}
}
}
}
FOR(i,1,m) {
if(!vis[i])chmax(bad, dfs(i));
}
done:;
if(bad)cout<<"NO\n";
else cout<<"YES\n";
FOR(i,1,m)vis[i]=0;
FOR(i,1,m)V[i].clear();
FOR(i,1,n)S[i]=T[i]=0;
FOR(i,1,n)adj[i].clear();
}
int32_t main()
{
IAMSPEED
cin >> q;
while(q--)solve();
}
Compilation message
jail.cpp: In function 'bool dfs(long long int)':
jail.cpp:114:6: warning: unused variable 'col' [-Wunused-variable]
114 | int col = 0;
| ^~~
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
11 ms |
24788 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
11 ms |
24788 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
11 ms |
24788 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
11 ms |
24788 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
11 ms |
24788 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
11 ms |
24660 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
11 ms |
24788 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
