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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#416537 | #8720. BFS 序 0 | Afterlife# | WA | 627ms | 101588kb | C++17 | 2.9kb | 2024-05-21 22:27:50 | 2024-05-21 22:27:51 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
const int N=1e6+1e3+7;
int n,st[N],ed[N],dep[N],dc;
vector<int> g[N];
int anc[N][21];
void dfs(int x,int f)
{
st[x]=++dc;
anc[x][0]=f;
for(int j=1;j<=20;j++)
anc[x][j]=anc[anc[x][j-1]][j-1];
for(auto v:g[x])
{
if(v==f)
continue;
dep[v]=dep[x]+1;
dfs(v,x);
}
ed[x]=dc;
}
int lca(int x,int y)
{
if(dep[x]<dep[y])
swap(x,y);
for(int i=20;i>=0;i--)
if(dep[x]-(1<<i)>=dep[y])
x=anc[x][i];
if(x==y)
return x;
for(int i=20;i>=0;i--)
if(anc[x][i]!=anc[y][i])
x=anc[x][i],y=anc[y][i];
return anc[x][0];
}
namespace SOLVE {
int m, i, a[N], q[N], t, tot;
int pos[N];
void dfs(int x)
{
for(auto v:g[x])
dfs(v),pos[x]=min(pos[x],pos[v]);
}
bool vip[N], vis[N];
bool cmp(int x, int y) { return st[x] < st[y]; }
vector<int> g[N];
void solve(vector<int> v,vector<int> seq) {
int la=-1;
bool ok=1;
for(auto x:seq)
{
if(dep[x]<la)
ok=0;
la=dep[x];
}
if (!v.size())
return;
vis[1] = vip[1] = a[1] = 1;
m = v.size();
for (tot = ++m, i = 2; i <= m; i++)
a[i] = v.back(), v.pop_back(), vis[a[i]] = vip[a[i]] = 1;
sort(a + 1, a + m + 1, cmp);
int x;
for (i = 1; i < m; i++)
if (!vis[x = lca(a[i], a[i + 1])])
vis[a[++tot] = x] = 1;
vector<int> use;
m = tot, sort(a + 1, a + m + 1, cmp);
for (q[t = 1] = 1, i = 2; i <= m; q[++t] = a[i++]) {
while (st[a[i]] < st[q[t]] || ed[a[i]] > ed[q[t]]) // dfs order
t--;
if (q[t] != a[i])
g[q[t]].push_back(a[i]);
use.push_back(q[t]);
use.push_back(a[i]);
}
for(auto x:use)
pos[x]=1e9;
// solve the problem
dfs(1);
for(int i=0;i<seq.size();i++)
pos[seq[i]]=i;
queue<int> q;
q.push(1);
auto it=seq.begin();
while(!q.empty())
{
int x=q.front();
q.pop();
if(it!=seq.end()&&x==*it)
it++;
sort(g[x].begin(),g[x].end(),[&](const int &a,const int &b){return pos[a]<pos[b];});
for(auto v:g[x])
q.push(v);
}
ok&=it==seq.end();
if(ok)
cout<<"Yes\n";
else
cout<<"No\n";
for (auto x : use)
vis[x] = vip[x] = 0, g[x].clear();
return;
}
} // namespace SOLVE
int main()
{
ios::sync_with_stdio(false);
cin.tie(0);
cin>>n;
for(int i=2;i<=n;i++)
{
int f;
cin>>f;
g[f].push_back(i);
}
dfs(1,0);
int m;
cin>>m;
while(m--)
{
int k;
cin>>k;
vector<int> s;
while(k--)
{
int x;
cin>>x;
s.push_back(x);
}
SOLVE::solve(s,s);
}
}
Details
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Test #1:
score: 100
Accepted
time: 16ms
memory: 64672kb
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: 627ms
memory: 101588kb
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 Yes No No No No Yes Yes No No No No No No No No No No No No No No Yes No No No Yes No No No No No No No No No Yes No No No No No No No No Yes No No Yes No No No No No No No No No No No No No No No Yes No No No Yes No No No No No No No Yes No No No Yes No No No No No No ...
result:
wrong answer expected YES, found NO [2nd token]