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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#603448 | #8720. BFS 序 0 | lllei | WA | 204ms | 76044kb | C++20 | 4.3kb | 2024-10-01 16:37:19 | 2024-10-01 16:37:21 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
using LL = long long;
struct LCA {
const int N;
int n, idx;
vector<int> id, rid, dep, fa;
vector<vector<int>> e, st;
LCA(int n) : N(__lg(n) + 1), n(n), idx(0), id(n, -1), rid(n), dep(n), fa(n), e(n), st(N, vector<int>(n)) {}
void add(int u, int v) {
e[u].push_back(v);
e[v].push_back(u);
}
int getMin(int x, int y) {
return dep[x] < dep[y] ? x : y;
}
void dfs(int u) {
id[u] = idx;
rid[idx] = u;
idx++;
for (int v : e[u]) {
if (id[v] != -1) {
continue;
}
dep[v] = dep[u] + 1;
fa[v] = u;
dfs(v);
}
}
void work(int rt = 0) {
dep[rt] = 1;
dfs(rt);
for (int i = 0; i < n; ++i) {
st[0][i] = rid[i];
}
for (int i = 1; i < N; ++i) {
for (int j = 0; j + (1 << i) - 1 < n; ++j) {
st[i][j] = getMin(st[i - 1][j], st[i - 1][j + (1 << (i - 1))]);
}
}
}
int getLca(int x, int y) {
if (x == y) {
return x;
}
x = id[x], y = id[y];
if (x > y) {
swap(x, y);
}
++x;
int z = __lg(y - x + 1);
return fa[getMin(st[z][x], st[z][y - (1 << z) + 1])];
}
};
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
int n;
cin >> n;
LCA lca(n);
vector<vector<int>> e(n);
for (int i = 1; i < n; ++i) {
int f;
cin >> f;
--f;
lca.add(f, i);
e[f].push_back(i);
}
lca.work();
vector<int> dep(n, -1);
vector<int> dfn(n);
int tot = 0;
auto dfs = [&](auto &&self, int u) -> void {
dfn[u] = tot++;
for (int v : e[u]) {
dep[v] = dep[u] + 1;
self(self, v);
}
};
dep[0] = 0;
dfs(dfs, 0);
int q;
cin >> q;
vector<vector<int>> ee(n);
vector<int> d(n);
auto solve = [&]() {
int m;
cin >> m;
vector<int> a(m);
vector<int> c(m);
for (int i = 0; i < m; ++i) {
cin >> a[i];
--a[i];
c[i] = a[i];
if (i) {
ee[a[i - 1]].push_back(a[i]);
d[a[i]]++;
}
}
for (int i = 1; i < m; ++i) {
if (dep[a[i]] < dep[a[i - 1]]) {
for (auto x : c) {
ee[x].clear();
d[x] = 0;
}
cout << "No\n";
return;
}
}
for (int i = 0; i < m; ++i) {
int j = i;
while (j < m && dep[a[j]] == dep[a[i]]) {
++j;
}
for (int k = i; k < j - 1; ++k) {
int l = lca.getLca(a[k], a[k + 1]);
int t1 = *prev(upper_bound(e[l].begin(), e[l].end(), a[k], [&](int x, int y) {
return dfn[x] < dfn[y];
}));
int t2 = *prev(upper_bound(e[l].begin(), e[l].end(), a[k + 1], [&](int x, int y) {
return dfn[x] < dfn[y];
}));
assert(t1 != t2);
ee[t1].push_back(t2);
d[t2]++;
c.push_back(t1);
c.push_back(t2);
}
i = j;
}
sort(c.begin(), c.end());
c.erase(unique(c.begin(), c.end()), c.end());
queue<int> q;
for (auto x : c) {
if (d[x] == 0) {
q.push(x);
}
}
int cnt = 0;
while (q.size()) {
int u = q.front();
q.pop();
++cnt;
for (int v : ee[u]) {
--d[v];
if (d[v] == 0) {
q.push(v);
}
}
}
for (auto x : c) {
ee[x].clear();
d[x] = 0;
}
if (cnt != c.size()) {
cout << "No\n";
} else {
cout << "Yes\n";
}
};
while (q--) {
solve();
}
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 0ms
memory: 3568kb
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: 204ms
memory: 76044kb
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 [181st token]