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QOJ
| ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
|---|---|---|---|---|---|---|---|---|---|
| #419229 | #8720. BFS 序 0 | tzxydby | WA | 194ms | 56148kb | C++20 | 2.0kb | 2024-05-23 19:14:34 | 2024-05-23 19:14:36 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
const int N=500005;
int n,m,q,fa[N][20],dep[N],a[N],d[N],ok,vis[N],c[N];
vector<int>e[N],g[N],p;
queue<int>qu;
void dfs(int u,int f)
{
fa[u][0]=f;
dep[u]=dep[f]+1;
for(auto v:e[u])
if(v!=f)
dfs(v,u);
}
int lca(int u,int v)
{
if(dep[u]<dep[v])
swap(u,v);
for(int i=18;i>=0;i--)
if(dep[fa[u][i]]>=dep[v])
u=fa[u][i];
if(u==v)
return u;
for(int i=18;i>=0;i--)
if(fa[u][i]!=fa[v][i])
u=fa[u][i],v=fa[v][i];
return fa[u][0];
}
int cal(int u,int v)
{
for(int i=18;i>=0;i--)
if(dep[fa[u][i]]>dep[v])
u=fa[u][i];
return u;
}
int main()
{
scanf("%d",&n);
for(int i=2;i<=n;i++)
{
int x;
scanf("%d",&x);
e[x].push_back(i);
}
dfs(1,0);
for(int j=1;j<=18;j++)
for(int i=1;i<=n;i++)
fa[i][j]=fa[fa[i][j-1]][j-1];
scanf("%d",&q);
while(q--)
{
scanf("%d",&m);
for(int i=1;i<=m;i++)
scanf("%d",&a[i]);
ok=1;
for(int i=1;i<=m;i++)
{
if(vis[a[i]])
ok=0;
vis[a[i]]=1;
}
for(int i=1;i<=m;i++)
vis[a[i]]=0;
for(int i=1;i<=m;i++)
d[i]=dep[a[i]];
for(int i=1;i<m;i++)
if(d[i]>d[i+1])
ok=0;
if(!ok)
{
puts("No");
continue;
}
for(int i=1;i<=m;i++)
{
int j=i;
while(j<m&&d[j+1]==d[i])
j++;
for(int k=i;k<j;k++)
{
int l=lca(a[k],a[k+1]);
int u=cal(a[k],l),v=cal(a[k+1],l);
p.push_back(u);
p.push_back(v);
g[u].push_back(v);
c[v]++;
}
sort(p.begin(),p.end());
p.erase(unique(p.begin(),p.end()),p.end());
for(auto u:p)
if(!c[u])
qu.push(u);
while(qu.size())
{
int u=qu.front();
qu.pop();
for(auto v:g[u])
{
c[v]--;
if(!c[v])
qu.push(v);
}
}
for(auto u:p)
if(c[u])
ok=0;
while(qu.size())
qu.pop();
for(auto u:p)
{
g[u].clear();
c[u]=0;
}
p.clear();
i=j;
if(!ok)
break;
}
puts(ok?"Yes":"No");
}
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 3ms
memory: 11872kb
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: 194ms
memory: 56148kb
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 Yes 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 Yes Yes Yes No No Yes No No No No No Yes Yes No No No No No Yes Yes No Yes No No No Yes No No Yes No No Yes Yes Yes No No No Y...
result:
wrong answer expected NO, found YES [181st token]