QOJ.ac

QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#416978#8720. BFS 序 0opbnbjsWA 232ms78304kbC++142.4kb2024-05-22 11:54:562024-05-22 11:54:57

Judging History

你现在查看的是最新测评结果

  • [2024-05-22 11:54:57]
  • 评测
  • 测评结果:WA
  • 用时:232ms
  • 内存:78304kb
  • [2024-05-22 11:54:56]
  • 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;
}
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);
		}
		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;
      }
		for(auto i:s){
         if(ind[i]==1)  continue;
         vis.clear();
			vis[i]=1;
			queue<int> q;
			q.push(i);
         V<int> vv;
			while(!q.empty()){
				int x = q.front();
            vv.pb(x);
				q.pop();
				for(auto j:f[x]){
					if(vis[j]==1){
						flag=0;
						cout<<"No\n";
						break;
					}
					vis[j]=1;
					q.push(j);
				}
				if(flag==0) break;
			}
			if(flag==0) break;
		}
		if(flag==0){
         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: 3ms
memory: 26304kb

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: 232ms
memory: 78304kb

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:

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

result:

wrong answer expected NO, found YES [1st token]