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QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#416988#8720. BFS 序 0opbnbjsWA 227ms78048kbC++142.5kb2024-05-22 12:08:242024-05-22 12:08:25

Judging History

你现在查看的是最新测评结果

  • [2024-05-22 12:08:25]
  • 评测
  • 测评结果:WA
  • 用时:227ms
  • 内存:78048kb
  • [2024-05-22 12:08:24]
  • 提交

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;
}
unordered_map<int,int> vis;
int ind[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;
		for(int i=1;i<=m;i++){
			int num;
			cin>>num;
			seq.pb(num);
		}
      if(m==1){
         cout<<"Yes\n";
         continue;
      }
		bool flag=1;
      set<int> s;
      set<int>ones;
		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);
         ind[b]=1;
         ones.insert(b);
         s.insert(a);
		}
		if(flag==0){
         for(auto i:s)  f[i].clear();
         for(auto i:ones)  ind[i]=0;
         continue;
      }
      flag=0;
		for(auto i:s){
         if(ind[i]==1)  continue;
         flag=1;
         vis.clear();
			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;
						break;
					}
					vis[j]=1;
					q.push(j);
				}
				if(flag==0) break;
			}
			if(flag==0) break;
		}
		if(flag==0){
			cout<<"No\n";
         for(auto i:s)  f[i].clear();
         for(auto i:ones)  ind[i]=0;
         continue;
      }
      for(auto i:s)  f[i].clear();
      for(auto i:ones)  ind[i]=0;
		cout<<"Yes\n";
	}
}
int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	solve();
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 0ms
memory: 28072kb

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: 227ms
memory: 78048kb

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
No
Yes
No
No
No
No
No
No
Yes
Yes
No
Yes
No
No
No
Yes
No
No
No
No
Yes
No
No
No
No
No
No
No
Yes
Yes
Yes
No
No
No
No
No
No
No
No
No
No
Yes
No
No
No
Yes
No
No
No
No
No
Yes
No
No
No
No
No
No
No
No
No
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Yes
No
No
Yes
Yes
No
No
No
No
No
No
No
No
No
...

result:

wrong answer expected YES, found NO [3rd token]