QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#416921 | #8720. BFS 序 0 | opbnbjs | WA | 173ms | 74708kb | C++14 | 2.2kb | 2024-05-22 11:12:21 | 2024-05-22 11:12:22 |
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);
while(!q.empty()){
int x = q.front();
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;
}
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
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Test #1:
score: 100
Accepted
time: 0ms
memory: 26600kb
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: 173ms
memory: 74708kb
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 No No No No No No No No No No No No Yes No Yes Yes No No No No No No No No Yes No No No No No Yes No No No Yes No No No No No No No Yes No Yes No No No No No No No Yes Yes No No Yes No No No No No No Yes No No No No No No No No Yes No No No Yes No No No No No Yes No Yes No No No Yes No No No No N...
result:
wrong answer expected YES, found NO [2nd token]