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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#602856 | #8720. BFS 序 0 | UESTC_DECAYALI# | WA | 168ms | 46212kb | C++20 | 2.6kb | 2024-10-01 13:11:04 | 2024-10-01 13:11:06 |
Judging History
answer
#include <bits/stdc++.h>
std::vector <int> G[300005];
int deg[300005];
void work() {
int n; std::cin >> n;
std::vector<int> pa(n, 0);
std::vector<std::vector<int>> ch(n), loop(n);
std::vector<int> dfn(n), dep(n);
for(int i = 1; i < n; ++i) std::cin >> pa[i], pa[i]--, ch[pa[i]].emplace_back(i);
int O = 0;
auto dfs = [&](auto dfs, int cur) -> void {
dfn[cur] = O++;
loop[cur].emplace_back(pa[cur]);
while(loop[cur].back() == 0) {
if(loop[loop[cur].back()].size() <= loop[cur].size()) break;
loop[cur].emplace_back(loop[loop[cur].back()][loop[cur].size() - 1]);
}
for(auto ch: ch[cur]) dep[ch] = dep[cur] + 1, dfs(dfs, ch);
};
auto lca = [&](int a, int b) -> int {
if(dep[a] < dep[b]) std::swap(a, b);
for(int i = 20; ~i; --i) if((dep[a] - dep[b]) & (1 << i)) a = loop[a][i];
if(a == b) return a;
for(int i = 20; ~i; --i) if(loop[a].size() > i && loop[a][i] != loop[b][i])
a = loop[a][i], b = loop[b][i];
return loop[a][0];
};
auto jump = [&](int &x, int step) {
assert(dep[x] >= step);
for (int i=20;i>=0;--i) if ((step>>i)&1) x=loop[x][i];
};
dep[0] = 0;
dfs(dfs, 0);
int q; std::cin >> q;
auto query = [&]() -> bool {
int m; std::cin >> m;
std::vector<int> b(m);
for(auto &b: b) std::cin >> b, b--;
std::vector <int> ext;
for (int i=0;i+1<m;++i)
if (dep[b[i+1]]<dep[b[i]]||b[i]==b[i+1]) return false;
for (int i=0;i+1<m;++i)
{
int x=b[i],y=b[i+1];
if (dep[x]!=dep[y]) continue;
int z=lca(x,y);
jump(x,dep[x]-dep[z]-1); jump(y,dep[y]-dep[z]-1);
ext.push_back(x); ext.push_back(y);
G[x].push_back(y); ++deg[y];
}
std::sort(ext.begin(),ext.end());
ext.erase(std::unique(ext.begin(),ext.end()),ext.end());
std::queue <int> Q; int cnt=0;
for (auto x:ext) if (!deg[x]) Q.push(x),++cnt;
while (!Q.empty())
{
int now=Q.front(); Q.pop();
for (auto to:G[now])
if (!--deg[to]) Q.push(to),++cnt;
}
for (auto x:ext) G[x].clear(),deg[x]=0;
return cnt==(int)ext.size();
};
while(q--) std::cout << (query() ? "Yes\n" : "No\n");
return ;
}
int main() {
// freopen("H.in","r",stdin);
std::ios::sync_with_stdio(false);
int T = 1; while(T--) work();
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 1ms
memory: 3796kb
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: 168ms
memory: 46212kb
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 Yes Yes No No No No No No Yes Yes No Yes No Yes Yes Yes No No No No Yes No No Yes No No No No Yes Yes Yes No No Yes No No No No No No No Yes No Yes No Yes No No No No Yes Yes Yes No No Yes No No No No No Yes Yes No No No No No Yes Yes No Yes No No No Yes No No Yes No No Yes Yes Yes No No No Y...
result:
wrong answer expected NO, found YES [176th token]