This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
// Super Idol的笑容
// 都没你的甜
// 八月正午的阳光
// 都没你耀眼
// 热爱105°C的你
// 滴滴清纯的蒸馏水
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>
using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
#define int long long
#define ll long long
#define ii pair<ll,ll>
#define iii pair<ii,ll>
#define fi first
#define se second
#define endl '\n'
#define debug(x) cout << #x << ": " << x << endl
#define pub push_back
#define pob pop_back
#define puf push_front
#define pof pop_front
#define lb lower_bound
#define ub upper_bound
#define rep(x,start,end) for(auto x=(start)-((start)>(end));x!=(end)-((start)>(end));((start)<(end)?x++:x--))
#define all(x) (x).begin(),(x).end()
#define sz(x) (int)(x).size()
#define indexed_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>
//change less to less_equal for non distinct pbds, but erase will bug
mt19937 rng(chrono::system_clock::now().time_since_epoch().count());
int n,q;
vector<int> al[120005];
int d[120005];
int tkd[120005][19];
ii idx[120005][19];
vector<int> al2[5000005];
int IDX;
void dfs(int i,int p){
for (auto it:al[i]){
if (it==p) continue;
d[it]=d[i]+1;
int curr=tkd[it][0]=i;
idx[it][0]={IDX,IDX+1};
al2[IDX++].clear();
al2[IDX++].clear();
rep(x,0,19){
if (tkd[curr][x]==-1) continue;
curr=tkd[it][x+1]=tkd[curr][x];
idx[it][x+1].fi=IDX;
al2[IDX].clear();
al2[IDX].pub(idx[it][x].fi);
al2[IDX].pub(idx[curr][x].fi);
IDX++;
idx[it][x+1].se=IDX;
al2[IDX].clear();
al2[idx[it][x].se].pub(IDX);
al2[idx[curr][x].se].pub(IDX);
IDX++;
}
dfs(it,i);
}
}
int mov(int i,int k){
rep(x,0,19) if (k&(1<<x)) i=tkd[i][x];
return i;
}
int lca(int i,int j){
if (d[i]<d[j]) swap(i,j);
i=mov(i,d[i]-d[j]);
if (i==j) return i;
rep(x,19,0) if (tkd[i][x]!=tkd[j][x]){
i=tkd[i][x];
j=tkd[j][x];
}
return tkd[i][0];
}
int dist(int i,int j){
int g=lca(i,j);
return d[i]+d[j]-2*d[g];
}
int vis[5000005];
bool cyc;
void dfs2(int i){
vis[i]=1;
for (auto it:al2[i]){
if (vis[it]==1) cyc=true;
if (vis[it]==0) dfs2(it);
}
vis[i]=2;
}
signed main(){
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin.exceptions(ios::badbit | ios::failbit);
int TC;
cin>>TC;
while (TC--){
cin>>n;
rep(x,1,n+1) al[x].clear();
int a,b;
rep(x,1,n){
cin>>a>>b;
al[a].pub(b);
al[b].pub(a);
}
cin>>q;
rep(x,0,q) al2[x].clear();
IDX=q;
idx[1][0]={IDX,IDX+1};
al2[IDX++].clear();
al2[IDX++].clear();
rep(x,1,n+1) rep(y,0,19) tkd[x][y]=-1;
dfs(1,-1);
//rep(x,1,n+1) cout<<idx[x][0].fi<<" "<<idx[x][0].se<<endl;
rep(i,0,q){
cin>>a>>b;
al2[i].pub(idx[a][0].fi);
al2[i].pub(idx[a][0].se);
al2[idx[b][0].fi].pub(i);
al2[idx[b][0].se].pub(i);
int g=lca(a,b);
if (a!=g){
int curr=tkd[a][0];
while (curr!=g){
al2[i].pub(idx[curr][0].fi);
al2[idx[curr][0].se].pub(i);
curr=tkd[curr][0];
}
}
if (b!=g){
int curr=tkd[b][0];
while (curr!=g){
al2[i].pub(idx[curr][0].fi);
al2[idx[curr][0].se].pub(i);
curr=tkd[curr][0];
}
}
if (g!=a && g!=b){
al2[i].pub(idx[g][0].fi);
al2[idx[g][0].se].pub(i);
}
}
// rep(x,0,IDX){
// for (auto y:al2[x]) cout<<x<<" "<<y<<endl;
// }
cyc=false;
rep(x,0,IDX) vis[x]=0;
rep(x,0,IDX) if (vis[x]==0) dfs2(x);
if (!cyc) cout<<"Yes"<<endl;
else cout<<"No"<<endl;
}
}
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |