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QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#469082#8720. BFS 序 0JEdwardWA 188ms89800kbC++172.6kb2024-07-09 13:17:552024-07-09 13:17:56

Judging History

你现在查看的是最新测评结果

  • [2024-07-09 13:17:56]
  • 评测
  • 测评结果:WA
  • 用时:188ms
  • 内存:89800kb
  • [2024-07-09 13:17:55]
  • 提交

answer

#include <bits/stdc++.h>
#define IOS ios::sync_with_stdio(0), cin.tie(0)
#define int long long
#define endl '\n'
#define lowbit(x) (x)&(-x)
#define pii pair<int,int>
#define all(s) s.begin(), s.end()
#define ls(x) (x<<1)
#define rs(x) (x<<1|1) 
#define here system("pause")
using namespace std;

const int N = 3e5+5;
const int mod = 1e9+7;
const int INF = 1e15+7;
const double eps = 1e-6;
inline int pow(int a, int b, int p){ int res = 1%p; while(b){ if(b&1) res=res*a%p; a=a*a%p, b>>=1;} return res;}
inline int inv(int a, int p){ return pow(a,p-2,p)%p;}

int n, q;
vector<int> g[N], pd[N];
int f[N][20], dep[N], ask[N<<1], indeg[N];
bool flag;

inline void dfs(int u, int fa){
	f[u][0] = fa;
	dep[u] = dep[fa] + 1;
	for(int i=1;i<20 && f[u][i-1];i++){
		f[u][i] = f[f[u][i-1]][i-1];
	}
	for(auto v:g[u]){
		if(v==fa) continue;
		dfs(v, u);
	}
}

inline int getlca(int u, int v){
	if(dep[u]<dep[v]) swap(u, v);
	for(int i=19;i>=0;i--){
		if(dep[f[u][i]]>=dep[v]) u = f[u][i];
	}
	
	if(u==v) return u;
	for(int i=19;i>=0;i--){
		if(f[u][i]!=f[v][i]) u = f[u][i], v = f[v][i];
	}
	return f[v][0];
}

inline void sol(){
	cin >> n;
	for(int i=2;i<=n;i++){
		cin >> f[i][0];
		g[f[i][0]].push_back(i);
		g[i].push_back(f[i][0]);
	}
	
	dfs(1, 0);
	cin >> q;
	while(q--){
		int num;
		cin >> num;
		flag = 1;
		vector<int> pot;
		for(int i=1;i<=num;i++){
			cin >> ask[i];
			if(ask[i-1]==ask[i]) flag = 0;
			if(i!=1 && dep[ask[i]] < dep[ask[i-1]]) flag = 0;
		}
		
		if(!flag){
			cout << "No\n";
			continue;
		}
		if(num==1){
			cout << "Yes\n";
			continue;
		}
		
		set<int> st;
		for(int i=2;i<=num;i++){
			if(dep[ask[i-1]]==dep[ask[i]]){
				st.insert(ask[i]), st.insert(ask[i-1]);
				pd[ask[i]].clear(), pd[ask[i-1]].clear();
				indeg[ask[i]] = indeg[ask[i-1]] = 0;
			}
		}
		
		for(int i=2;i<=num;i++){
			if(dep[ask[i-1]]==dep[ask[i]]){
				int a = ask[i-1], b = ask[i];
				//cout << getlca(a, b) << " <- " << a << ", " << b << '\t';
				for(int j=19;j>=0;j--){
					if(f[j][a] != f[j][b]) a = f[j][a], b = f[j][b];
				}
				//cout << a << ", " << b << endl;
				
				pd[a].push_back(b);
				++indeg[b];
			}
		}
		
		queue<int> q;
		for(int k:st){
			if(!indeg[k]) q.push(k);
		}
		
		while(q.size()){
			int now = q.front();
			q.pop();
			for(int k:pd[now]){
				--indeg[k];
				if(!indeg[k]) q.push(k);
			}
		}
		
		for(int k:st){
			if(indeg[k]) flag = 0;
			//cout << " " << k << ": " << indeg[k] << endl;
		}
		if(!flag) cout << "No\n";
		else cout << "Yes\n";
	}
}

signed main(){
	IOS;
	int tc = 1;
	while(tc--){
		sol();
	}
	return 0;
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 0ms
memory: 23776kb

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: 188ms
memory: 89800kb

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
Yes
Yes
No
Yes
Yes
No
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
No
Yes
No
No
Yes
Yes
Yes
Yes
No
Yes
Yes
No
No
No
Yes
No
Yes
Yes
No
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Yes
Yes
No
No
Yes
No
Yes
Yes
No
Yes
No
Yes
Yes
No
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Y...

result:

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