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IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#416602#8720. BFS 序 0Afterlife#WA 560ms814084kbC++173.5kb2024-05-21 23:54:022024-05-21 23:54:04

Judging History

This is the latest submission verdict.

  • [2024-05-21 23:54:04]
  • Judged
  • Verdict: WA
  • Time: 560ms
  • Memory: 814084kb
  • [2024-05-21 23:54:02]
  • Submitted

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];
  queue<int> Q[N];
  vector<int> h[N];
  int deg[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(!ok)
    {
        cout<<"No\n";
        return;
    }
    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]);
    }
    sort(use.begin(),use.end());
    use.erase(unique(use.begin(),use.end()),use.end());
    for(auto x:use)
        h[x].clear(),h[x+n].clear(),deg[x]=0,deg[x+n]=0;
    for(auto x:use)
    {
        h[x+n].push_back(x);
        ++deg[x];
        for(auto y:g[x])
        {
            h[y].push_back(x);
            ++deg[x];
            h[x+n].push_back(y+n);
            ++deg[y+n];
        }
    }
    for(int i=0;i+1<seq.size();i++)
    {
        int x=seq[i],y=seq[i+1];
        if(dep[x]!=dep[y])
            continue;
        h[x].push_back(y+n);
        ++deg[y+n];
    }
    queue<int> q;
    for(auto x:use)
    {
        if(!deg[x])
            q.push(x);
        if(!deg[x+n])
            q.push(x+n);
    }
    int cnt=0;
    while(!q.empty())
    {
        int x=q.front();
        q.pop();
        ++cnt;
        for(auto v:h[x])
            if(!--deg[v])
                q.push(v);
    }
    ok&=cnt==use.size()*2;
    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: 132ms
memory: 759736kb

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: 560ms
memory: 814084kb

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
Yes
No
No
...

result:

wrong answer expected NO, found YES [87th token]