QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#451925 | #8720. BFS 序 0 | JEdward | TL | 0ms | 13832kb | C++17 | 2.6kb | 2024-06-23 17:46:47 | 2024-06-23 17:46:47 |
Judging History
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];
int f[N][20], dep[N], ask[N<<1];
bool flag;
map<int, int> mp;
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 dfs1(int u, vector<vector<int>>& pd, map<int, pii>& deg){
if(mp[u]>deg[u].first){flag = 0; return ;}
for(auto v:pd[u]) mp[v]++, dfs1(v, pd, deg);
}
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;
for(int i=1;i<=num;i++){
cin >> ask[i];
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;
}
vector<vector<int>> pd(n+1);
map<int, pii> deg; // pii -> in & out
for(int i=2;i<=num;i++){
if(dep[ask[i-1]]<dep[ask[i]]) continue;
else if(dep[ask[i-1]]==dep[ask[i]]){
int lca = getlca(ask[i-1], ask[i]);
int a, b;
for(int k:g[lca]){
if(k==f[lca][0]) continue;
if(k==ask[i-1]) a = k;
if(k==ask[i]) b = k;
for(int j=0;j<20;j++){
if(k==f[ask[i-1]][j]) a = k;
if(k==f[ask[i]][j]) b = k;
}
}
pd[a].push_back(b);
deg[a].second++;
deg[b].first++;
mp.clear();
bool haveS = 0;
for(auto k:deg){
if(k.second.first==0 && k.second.second!=0)
dfs1(k.first, pd, deg), haveS = 1;
}
if(deg.size() && !haveS) flag = 0;
}
if(!flag) cout << "No\n";
else cout << "Yes\n";
}
}
}
signed main(){
IOS;
int tc = 1;
while(tc--){
sol();
}
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 0ms
memory: 13832kb
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
Time Limit Exceeded
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 Yes Yes 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 Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Y...