QOJ.ac

QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#589481#8720. BFS 序 0tarjen#WA 2687ms70040kbC++202.3kb2024-09-25 18:07:032024-09-25 18:07:03

Judging History

你现在查看的是最新测评结果

  • [2024-09-25 18:07:03]
  • 评测
  • 测评结果:WA
  • 用时:2687ms
  • 内存:70040kb
  • [2024-09-25 18:07:03]
  • 提交

answer

#include <bits/stdc++.h>
using namespace std;
const int maxn=3e5+10;
vector<int>ve[maxn];
int dep[maxn],f[21][maxn];
void dfs(int x,int fa)
{
	dep[x]=dep[fa]+1;
	for(int i=0;i<=19;i++)
		f[i+1][x]=f[i][f[i][x]];
    for(auto it:ve[x])
	{
		if(it==fa) continue;
		f[0][it]=x;
		dfs(it,x);
	}
}
int lca(int x,int y)
{
	if(dep[x]<dep[y]) swap(x,y);
	for(int i=20;i>=0;i--)
	{
		if(dep[f[i][x]]>=dep[y]) x=f[i][x];
		if(x==y) return x;
	}
	for(int i=20;i>=0;i--)
		if(f[i][x]!=f[i][y])
			x=f[i][x],y=f[i][y];
	return f[0][x];
}
int findk(int x,int k){
    for(int i=20;i>=0;i--)if(k>>i&1)x=f[i][x];
    return x;
}
vector<int> ve2[maxn];
int cnt[maxn];
bool check(vector<pair<int,int>> &edges){
    set<int> s;
    for(auto [x,y]:edges)s.insert(x),s.insert(y),ve2[x].push_back(y);
    vector<int> v(s.begin(),s.end());
    for(auto [x,y]:edges)cnt[y]++;
    queue<int> qu;
    for(auto it:v)if(cnt[it]==0)qu.push(it);
    int all=(int)edges.size();
    while(!qu.empty()){
        int x=qu.front();qu.pop();
        for(auto it:ve2[x]){
            if((--cnt[it])==0)qu.push(it);
            all--;
        }
    }
    for(auto it:v)cnt[it]=0,ve2[it].clear();
    return all==0;
}
void solve()
{
    int n;cin>>n;
    for(int i=1;i<=n;i++)ve[i].clear();
    for(int i=2;i<=n;i++){
        int x;cin>>x;
        ve[x].push_back(i);
        ve[i].push_back(x);
    }
    dfs(1,0);
    vector<vector<pair<int,int>>> edges(n+1);
    auto sol = [&]()
    {
        int len;cin>>len;
        vector<int> a(len);
        set<int> s;
        for(int i=0;i<len;i++)cin>>a[i],s.insert(a[i]);
        if((int)s.size()!=len)return "No";
        for(int i=0;i+1<len;i++)if(dep[a[i]]>dep[a[i+1]])return "No";
        vector<int> in;
        for(int i=0;i+1<len;i++)if(dep[a[i]]==dep[a[i+1]]){
            int l=lca(a[i],a[i+1]);
            in.push_back(l);
            edges[l].emplace_back(findk(a[i],dep[a[i]]-dep[l]-1),findk(a[i+1],dep[a[i+1]]-dep[l]-1));
        }
        sort(in.begin(),in.end());
        for(auto it:in)if(!check(edges[it]))return "No";
        for(auto it:in)edges[it].clear();
        return "Yes";
    };
    int q;cin>>q;
    while(q--){
        cout<<sol()<<"\n";
    }
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    int T=1;while(T--)solve();
    return 0;
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 0ms
memory: 26120kb

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: 2687ms
memory: 70040kb

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 YES, found NO [93rd token]