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QOJ
| ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
|---|---|---|---|---|---|---|---|---|---|
| #416202 | #8720. BFS 序 0 | wwxyy2005 | WA | 85ms | 36756kb | C++14 | 1.8kb | 2024-05-21 17:32:53 | 2024-05-21 17:32:53 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
const int N = 3e5 + 10;
int n, q, dep[N], fa[20][N], head[N], cnt, m, a[N];
int top, id[N], in[N];
struct Edge{
int to, nxt;
}edge[N << 1];
void add(int u, int v){
edge[++cnt] = (Edge){v, head[u]};
head[u] = cnt;
}
void dfs(int now, int father, int deep){
dep[now] = deep;
for(int i = head[now]; i; i = edge[i].nxt){
if(edge[i].to == father) continue;
dfs(edge[i].to, now, deep + 1);
}
}
queue<int> st;
int main()
{
ios::sync_with_stdio(0);
cin >> n;
for(int i = 2; i <= n; ++i) cin >> fa[0][i], add(fa[0][i], i);
dfs(1, 0, 1);
for(int j = 1; j <= 19; ++j)
for(int i = 1; i <= n; ++i) fa[j][i] = fa[j - 1][fa[j - 1][i]];
memset(head, 0, sizeof(head));
cin >> q;
while(q--){
cin >> m;
for(int i = 1; i <= m; ++i) cin >> a[i];
bool flag = true;
for(int i = 1; i < m; ++i){
if(dep[a[i]] > dep[a[i + 1]]){flag = false; break;}
}
if(!flag){
cout << "No" << endl;
continue;
}
for(int i = 1; i < m; ++i){
if(dep[a[i]] != dep[a[i + 1]]) continue;
int u = a[i], v = a[i + 1];
for(int j = 19; j >= 0; --j) if(fa[j][u] != fa[j][v]) u = fa[j][u], v = fa[j][v];
add(u, v);
id[++top] = u, id[++top] = v; in[v]++;
}
top = unique(id + 1, id + 1 + top) - id - 1;
for(int i = 1; i <= top; ++i) if(!in[id[i]]) st.push(id[i]);
while(!st.empty()){
int now = st.front();
st.pop();
for(int i = head[now]; i; i = edge[i].nxt){
in[edge[i].to]--;
if(!in[edge[i].to]) st.push(edge[i].to);
}
}
for(int i = 1; i <= top; ++i) if(in[id[i]]){flag = false; break;}
if(flag) cout << "Yes" << endl;
else cout << "No" << endl;
for(int i = 1; i <= top; ++i) in[id[i]] = 0, head[id[i]] = 0;
top = 0, cnt = 0;
}
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 2ms
memory: 30356kb
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: 85ms
memory: 36756kb
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 No No No No No No No Yes Yes No Yes No Yes Yes Yes No No No No No No No Yes No No No No Yes Yes No No No Yes No No No No No No No Yes No Yes No Yes No No No No No Yes Yes No No Yes No No No No No Yes Yes No No No No No No No No Yes No No No Yes No No Yes No No Yes No Yes No No No Yes No No...
result:
wrong answer expected YES, found NO [3rd token]