QOJ.ac
QOJ
| ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
|---|---|---|---|---|---|---|---|---|---|
| #422136 | #8720. BFS 序 0 | MaxDYF | WA | 148ms | 55388kb | C++23 | 2.4kb | 2024-05-26 20:27:24 | 2024-05-26 20:27:25 |
Judging History
answer
// #pragma GCC optimize(2)
#include <bits/stdc++.h>
using namespace std;
const int N = 3e5 + 10;
const int inf = 1 << 30;
const long long llinf = 1ll << 60;
const double PI = acos(-1);
#define lowbit(x) (x & -x)
typedef long long ll;
typedef double db;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<db, db> pdd;
typedef pair<ll, int> pli;
int n, m, k, q;
int f[N][25];
vector<int> G[N];
int dep[N];
void dfs(int x)
{
dep[1] = 1;
for (int i = 1; i < 25; i++)
f[x][i] = f[f[x][i - 1]][i - 1];
for (auto y : G[x])
{
f[y][0] = x;
dep[y] = dep[x] + 1;
dfs(y);
}
}
int lca(int x, int y)
{
if (x == y)
return x;
if (dep[x] < dep[y])
swap(x, y);
for (int i = 24; i >= 0; i--)
if (dep[f[x][i]] >= dep[y])
x = f[x][i];
if (x == y)
return x;
for (int i = 24; i >= 0; i--)
if (f[x][i] != f[y][i])
{
x = f[x][i];
y = f[y][i];
}
return f[x][0];
}
vector<int> G1[N];
int jump(int x, int fa)
{
int stp = dep[x] - dep[fa] - 1;
for (int i = 24; i >= 0; i--)
{
if (stp & (1 << i))
x = f[x][i];
}
return x;
}
bool vis[N];
void work()
{
cin >> n;
for (int y = 2; y <= n; y++)
{
int x;
cin >> x;
G[x].push_back(y);
}
dfs(1);
cin >> q;
for (int t = 1; t <= q; t++)
{
cin >> m;
vector<int> arr(m), vec;
auto clear = [&]()
{
for (auto x : vec)
{
G1[x].clear();
vis[x] = 0;
}
};
for (int i = 0; i < m; i++)
cin >> arr[i];
bool ok = 1;
for (int i = 1; i < m; i++)
{
int x = arr[i - 1], y = arr[i];
if (dep[x] > dep[y])
{
ok = 0;
break;
}
if (dep[x] != dep[y])
continue;
int anc = lca(x, y);
int x1 = jump(x, anc);
int x2 = jump(y, anc);
vec.push_back(x1);
vec.push_back(x2);
G1[x1].push_back(x2);
}
if (!ok)
{
cout << "No\n";
clear();
continue;
}
auto checkRing = [&](auto &checkRing, int x)
{
if (vis[x])
return false;
vis[x] = true;
for (auto y : G1[x])
{
if (!checkRing(checkRing, y))
return false;
}
return true;
};
for (auto x : vec)
if (ok && !vis[x] && !checkRing(checkRing, x))
{
ok = false;
break;
}
cout << (ok ? "Yes\n" : "No\n");
clear();
}
}
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int t = 1;
while (t-- > 0)
{
work();
}
}
Details
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Test #1:
score: 100
Accepted
time: 2ms
memory: 5684kb
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: 148ms
memory: 55388kb
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 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 [2nd token]