QOJ.ac
QOJ
| ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
|---|---|---|---|---|---|---|---|---|---|
| #416937 | #8720. BFS 序 0 | opbnbjs | WA | 191ms | 74784kb | C++14 | 2.3kb | 2024-05-22 11:19:01 | 2024-05-22 11:19:01 |
Judging History
answer
#include<bits/stdc++.h>
#define V vector
#define pb push_back
#define mp make_pair
#define F first
#define S second
using namespace std;
const int maxn = 3e5+5;
int fno[maxn][35],dep[maxn];
V<int> g[maxn];
void dfs(int x,int fa){
dep[x] = dep[fa]+1;
fno[x][0] = fa;
for(int i=1;i<=30;i++){
fno[x][i] = fno[fno[x][i-1]][i-1];
}
for(auto i:g[x]){
if(i==fa) continue;
dfs(i,x);
}
}
set<int> f[maxn];
int lca(int x,int y){
if(dep[x]>dep[y]) swap(x,y);
int dif = dep[y]-dep[x];
for(int i=0;dif;i++,dif>>=1){
if(dif&1==1) y = fno[y][i];
}
if(x==y) return x;
for(int i=30;i>=0&&y!=x;i--){
if(fno[x][i]!=fno[y][i]){
x = fno[x][i];
y = fno[y][i];
}
}
return fno[x][0];
}
int getfa(int x,int y){
if(dep[x]>dep[y]) swap(x,y);
int dif = dep[y]-dep[x]-1;
for(int i=0;dif;i++,dif>>=1){
if(dif&1==1) y = fno[y][i];
}
if(x==fno[y][0]) return y;
}
bool vis[maxn];
void solve(){
int n;
cin>>n;
for(int i=2;i<=n;i++){
int fa;
cin>>fa;
g[fa].pb(i);
}
dfs(1,0);
int q;
cin>>q;
while(q--){
int m;
cin>>m;
V<int> seq;
memset(vis,0,sizeof(vis));
for(int i=1;i<=m;i++){
int num;
cin>>num;
seq.pb(num);
}
bool flag=1;
set<int> s;
for(int i=1;i<seq.size();i++){
if(dep[seq[i]]<dep[seq[i-1]]){
cout<<"No\n";
flag=0;
break;
}
if(dep[seq[i]]>dep[seq[i-1]]) continue;
int l = lca(seq[i],seq[i-1]);
int a,b;
a = getfa(l,seq[i-1]);
b = getfa(l,seq[i]);
f[a].insert(b);
s.insert(a);
}
if(flag==0){
for(auto i:s) f[i].clear();
continue;
}
for(auto i:s){
if(vis[i]==1) continue;
vis[i]=1;
queue<int> q;
q.push(i);
V<int> vv;
while(!q.empty()){
int x = q.front();
vv.pb(x);
q.pop();
for(auto j:f[x]){
if(vis[j]==1){
flag=0;
cout<<"No\n";
break;
}
vis[j]=1;
q.push(j);
}
if(flag==0) break;
}
for(auto i:vv) vis[i]=0;
if(flag==0) break;
}
if(flag==0){
for(auto i:s) f[i].clear();
continue;
}
for(auto i:s) f[i].clear();
cout<<"Yes\n";
}
}
int main(){
ios::sync_with_stdio(false);
cin.tie(0);
solve();
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 0ms
memory: 28260kb
input:
6 1 1 3 2 4 10 4 3 6 2 5 1 4 3 2 4 5 5 2 5 4 6 3 3 1 4 2 3 5 6 3 5 4 5 2 6 1 4 4 3 2 5 4 4 6 2 3 3 3 2 6
output:
No Yes Yes No No No No No No Yes
result:
ok 10 token(s): yes count is 3, no count is 7
Test #2:
score: -100
Wrong Answer
time: 191ms
memory: 74784kb
input:
300000 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1...
output:
No Yes No Yes No No No No No No Yes Yes No Yes No Yes Yes Yes No No No No Yes No No Yes No No No No Yes Yes Yes No No Yes No No No No No No No Yes No Yes No Yes No No No No No Yes Yes No No Yes No No No No No Yes Yes No No No No No No No No Yes No No No Yes No No Yes No No Yes Yes Yes No No No Yes N...
result:
wrong answer expected YES, found NO [3rd token]