QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#602638 | #8720. BFS 序 0 | ucup-team902# | WA | 180ms | 52664kb | C++23 | 2.7kb | 2024-10-01 11:26:42 | 2024-10-01 11:26:43 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
int n;
vector<int> G[400005], G2[400005];
int fa[400005][20];
int dep[400005], b[400005];
int LCA(int u, int v) {
if (dep[u] < dep[v]) swap(u, v);
for (int i = 19; ~i; i--)
if (dep[fa[u][i]] >= dep[v]) u = fa[u][i];
if (u == v) return v;
for (int i = 19; ~i; i--)
if (fa[u][i] != fa[v][i]) {
u = fa[u][i], v = fa[v][i];
}
return fa[u][0];
}
int dis(int u, int v) {
return dep[u] + dep[v] - 2 * dep[LCA(u, v)];
}
int jumpfa(int u, int dis) {
for (int i = 19; ~i; i--)
if (dis >= (1 << i)) u = fa[u][i], dis -= (1 << i);
return u;
}
void dfs(int u) {
for (int i = 1; i < 20; i++) fa[u][i] = fa[fa[u][i - 1]][i - 1];
for (int v : G[u]) {
fa[v][0] = u;
dep[v] = dep[u] + 1;
dfs(v);
}
}
int deg[400005];
bool topsort(vector<int> pt) {
for (int x : pt) deg[x] = 0;
for (int x : pt) {
for (int v : G2[x]) deg[v]++;
}
queue<int> q;
int cnt = 0;
for (int x : pt) {
if (deg[x] == 0) q.push(x);
}
while (!q.empty()) {
int x = q.front();
q.pop();
cnt++;
for (int v : G2[x]) {
deg[v]--;
if (deg[v] == 0) q.push(v);
}
}
return cnt == (int)pt.size();
}
int dd[400005];
void solve() {
cin >> n;
for (int i = 2; i <= n; ++i) {
int x;
cin >> x, G[x].push_back(i);
}
dfs(1);
// for (int i = 1; i <= n; ++i) cout << dep[i] << endl;
int q;
cin >> q;
for (int tt = 1; tt <= q; ++tt) {
int m;
cin >> m;
vector<int> a(m);
for (int i = 0; i < m; ++i) cin >> a[i];
bool flag = 1;
for (int i = 1; i < m; ++i) {
if (dep[a[i]] < dep[a[i - 1]]) flag = 0;
}
if (flag) {
vector<int> vis;
for (int i = 1; i < m; ++i) {
int x = a[i-1], y = a[i];
if (dep[x] != dep[y]) continue;
if (dd[x] == tt) flag = 0;
dd[x] = tt;
int Lca = LCA(x, y);
int xx = jumpfa(x, dep[x] - dep[Lca] - 1), yy = jumpfa(y, dep[y] - dep[Lca] - 1);
// cout << xx << " " << x << " " << yy << " " << y << " " << Lca << endl;
G2[xx].push_back(yy);
vis.push_back(xx);
vis.push_back(yy);
}
if (flag) flag = topsort(vis);
for (int v : vis) G2[v].clear();
}
cout << (flag ? "Yes" : "No") << endl;
}
}
int main() {
ios::sync_with_stdio(false);
int T = 1;
while (T--) {
solve();
}
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 0ms
memory: 5664kb
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: 180ms
memory: 52664kb
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 No No No No No No No No No No No No No No Yes Yes No No No No No No No No Yes No No No No No Yes No No No Yes No No No No No No No Yes No Yes No No No No No No No Yes Yes No No Yes No No No No No No Yes No No No No No No No No Yes No No No Yes No No No No No No No Yes No No No Yes No No No No No ...
result:
wrong answer expected YES, found NO [2nd token]