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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#805755 | #8551. DFS Order 5 | kjhhjki# | WA | 30ms | 3832kb | C++20 | 3.7kb | 2024-12-08 18:24:19 | 2024-12-08 18:24:20 |
Judging History
answer
#include <bits/stdc++.h>
template<typename T, typename U>
void chkmin(T &a, U b) { if (a > b) a = b; }
using i64 = long long;
struct Fenwick {
int n;
std::vector<int> t;
Fenwick(int _n = 0, int x = 0) { init(std::vector<int>(_n + 1, x)); }
Fenwick(const std::vector<int> &a) { init(a); }
static constexpr int lowbit(int x) { return x & -x; }
void init(const std::vector<int> &a) {
n = a.size() - 1;
t.assign(n + 1, 0);
for (int i = 1; i <= n; ++i) {
t[i] += a[i];
if (i + lowbit(i) <= n) {
t[i + lowbit(i)] += t[i];
}
}
}
void add(int i, int k) { while (i <= n) t[i] += k, i += lowbit(i); }
int query(int i) { int ans = 0; while (i) ans += t[i], i -= lowbit(i); return ans; }
int query(int l, int r) { return query(r) - query(l - 1); }
};
void solve()
{
int n, q;
std::cin >> n >> q;
std::vector<std::vector<int>> adj(n);
for (int i = 1; i < n; ++i) {
int u, v;
std::cin >> u >> v;
adj[--u].push_back(--v);
adj[v].push_back(u);
}
std::vector<int> dfn(n, -1), seq = dfn, top(n), dep(n), pre = dfn, sz(n, 1);
auto dfs1 = [&](auto &&self, int u) -> void {
if (pre[u] != -1) {
adj[u].erase(std::ranges::find(adj[u], pre[u]));
}
for (auto &v: adj[u]) {
dep[v] = dep[u] + 1;
pre[v] = u;
self(self, v);
sz[u] += sz[v];
if (sz[v] > sz[adj[u][0]]) {
std::swap(v, adj[u][0]);
}
}
};
dfs1(dfs1, 0);
int t = 0;
auto dfs2 = [&](auto &&self, int u) -> void {
dfn[u] = t; seq[t++] = u;
for (auto v: adj[u]) {
top[v] = (v == adj[u][0]? top[u]: v);
self(self, v);
}
};
dfs2(dfs2, 0);
auto lca = [&](int u, int v) {
while (top[u] != top[v]) {
if (dep[top[u]] < dep[top[v]]) {
v = pre[top[v]];
} else {
u = pre[top[u]];
}
}
return dep[u] < dep[v]? u: v;
};
auto cmp = [&](int u, int v) { return dfn[u] < dfn[v]; };
auto find = [&](int u, int v) {
auto it = std::ranges::lower_bound(adj[u], v, cmp);
return it != adj[u].end() && *it == v;
};
std::vector<bool> vis(n);
while (q --) {
int k;
std::cin >> k;
std::vector<int> v(k), st;
for (auto &x: v) {
std::cin >> x;
--x;
vis[x] = false;
}
bool f = true;
for (int i = 0; i < k; ++i) {
if ((!st.empty()) && !find(v[st.back()], v[i])) {
int p = lca(v[st.back()], v[i]);
if (!find(p, v[i])) {
f = false;
break;
}
while (!st.empty()) {
int t = st.back();
if (p == v[t]) {
break;
}
st.pop_back();
if (i - t < sz[v[t]]) {
f = false;
break;
}
}
}
if (!f) {
break;
}
st.push_back(i);
vis[v[i]] = true;
}
std::cout << (f? "Yes": "No") << '\n';
}
}
int main()
{
std::ios::sync_with_stdio(false);
std::cin.tie(nullptr);
int T = 1;
// std::cin >> T;
while (T --) solve();
return 0;
}
/*
6 1
1 2
1 3
2 4
3 5
2 6
2 4 1
2 4 2
2 4 3
2 4 4
2 4 5
2 4 6
6 1 2 6 4 3 5
*/
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 0ms
memory: 3532kb
input:
6 7 1 2 1 3 2 4 3 5 2 6 2 4 1 2 4 2 2 4 3 2 4 4 2 4 5 2 4 6 6 1 2 6 4 3 5
output:
No No Yes No No Yes Yes
result:
ok 7 tokens
Test #2:
score: -100
Wrong Answer
time: 30ms
memory: 3832kb
input:
10 100000 7 2 1 7 7 10 8 6 8 7 1 3 4 5 9 5 5 8 8 8 9 7 2 8 1 6 1 4 8 3 5 2 6 7 10 3 9 9 1 1 1 8 10 3 2 9 3 8 7 3 7 5 6 2 8 5 9 1 6 3 4 6 2 1 3 5 8 9 2 4 9 1 3 2 1 5 5 8 5 1 7 9 10 5 2 9 2 6 4 10 6 3 8 3 4 5 8 2 8 4 9 4 10 1 2 4 3 3 6 3 1 3 6 1 1 6 8 3 1 3 7 3 2 3 9 1 5 4 3 7 8 10 9 4 2 3 10 2 5 4 3 ...
output:
No No No Yes No No No No Yes No No No No No No Yes No No No No No No No No No No No No No No No Yes No No No No No No Yes No No No No No Yes Yes No No No No No No No No No No No No No No No No No No No No No No No No Yes No No Yes Yes No No No No Yes No No No No No No No No Yes No No No No No No No ...
result:
wrong answer 89th words differ - expected: 'No', found: 'Yes'