#include <iostream>
#include <cstring>
#include <vector>
#include <algorithm>
#include <deque>
#include <set>
#include <utility>
#include <array>
using namespace std;
#define ALL(x) x.begin(), x.end()
#define ShinLena cin.tie(nullptr)->sync_with_stdio(false);
using i64 = long long;
#define N 200005
int n, d, l[N], h[N], alloc = 1, dp[N][2], t[N<<1];
pair<int, int> g[N<<1];
void upd(int p, int k) {
p += 3;for (; p ; p-=p&-p) t[p] += k;
}
int qry(int p) { p += 3; int z = 0; for (; p < N; p+=p&-p) z += t[p]; return z; }
void add_edge(int u, int v)
{
int p = alloc++;
g[p] = {v, h[u]};
h[u] = p;
}
void dfs(int u, int p, int dep)
{
l[u] = dep;
int base = 0, lowest = 1e9;
for (auto j = h[u]; j; j = g[j].second)
{
int v = g[j].first;
if (v == p) continue;
dfs(v, u, dep+1);
base += dp[v][0] - 1;
upd(dp[v][1], 1);
lowest = min(lowest, dp[v][1]);
}
dp[u][0] = base, dp[u][1] = lowest;
{
int sel = base + 1 + qry(d + dep);
if (dp[u][0] < sel) dp[u][0] = sel, dp[u][1] = dep;
else if (dp[u][0] == sel && dep > dp[u][1]) dp[u][1] = dep;
}
for (auto j = h[u]; j; j = g[j].second)
{
int v = g[j].first;
if (v == p) continue;
int delta = dp[v][1] - dep;
int safe = (d+1)/2;
if (delta >= safe)
{
int sel = base + qry(dep + safe);
if (dp[u][0] < sel)
dp[u][0] = sel, dp[u][1] = dp[v][1];
else if (dp[u][0] == sel && dp[v][1] > dp[u][1])
dp[u][1] = dp[v][1];
}
else
{
int sel = base + 1 + qry(dep + max(safe, d- delta));
if (dp[u][0] < sel)
dp[u][0] = sel, dp[u][1] = dp[v][1];
else if (dp[u][0] == sel && dp[v][1] > dp[u][1])
dp[u][1] = dp[v][1];
}
}
for (auto j = h[u]; j; j = g[j].second)
{
int v = g[j].first;
if (v != p) upd(dp[v][1], -1);
}
}
int main()
{
ShinLena;
cin >> n >> d;
for (int i = 1, v; i < n; ++i) cin >> v, add_edge(v, i);
dfs(0, 0, 1);
for (int i = 0; i < n; ++i)
{
//cerr << dp[i][0] << ' '<< dp[i][1] << ' ' <<l[i] <<endl;
}
cout << dp[0][0];
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
0 ms |
344 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
0 ms |
344 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
0 ms |
344 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |