#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define F first
#define S second
#define pb push_back
#define endl "\n"
#define all(x) x.begin(), x.end()
const int M = 2000007;
const ll inf = 1e9;
const ll mod = 998244353;
const double pi = acos(-1);
const int dx[] = {1, 0, -1, 0}, dy[] = {0, 1, 0, -1};
vector < pair <int,int> > v;
vector <int> adj[M];
int n, d, p[M], mn[M], sz[M], add[M], dep[M], dist, ans;
bool vist[M];
void calc(int node, int par)
{
sz[node] = 1;
for(auto i : adj[node]) if(i != par && !vist[i]){
calc(i, node);
sz[node] += sz[i];
}
return;
}
int get(int node, int par, int half)
{
++dist;
for(auto i : adj[node]) if(!vist[i] && i != par && sz[i] > half) return get(i, node, half);
return node;
}
void decompose(int node, int par)
{
dist = 0;
calc(node, 0);
int cen = get(node, 0, sz[node] / 2);
vist[cen] = 1;
p[cen] = par;
add[cen] = dist;
for(auto i : adj[cen]) if(!vist[i]) decompose(i, cen);
return;
}
void dfs(int node, int par)
{
v.pb({dep[node], node});
for(auto i : adj[node]) if(i != par){
dep[i] = dep[node] + 1;
dfs(i, node);
}
return;
}
int main()
{
scanf("%d%d", &n, &d);
for(int i = 2; i <= n; ++i){
int a;
scanf("%d", &a);
adj[a + 1].pb(i);
adj[i].pb(a + 1);
}
decompose(1, 0);
dfs(1, 0);
sort(all(v), greater < pair <int,int> > ());
for(int i = 1; i <= n; ++i) mn[i] = inf;
for(auto i : v){
bool ok = 1;
int cur = i.S;
dist = 0;
while(cur){
if(mn[cur] + dist < d) ok = 0;
dist += add[cur];
cur = p[cur];
}
if(ok){
++ans;
cur = i.S; dist = 0;
while(cur){
mn[cur] = min(mn[cur], dist);
dist += add[cur];
cur = p[cur];
}
}
}
printf("%d\n", ans);
return 0;
}
Compilation message
catinatree.cpp: In function 'int main()':
catinatree.cpp:61:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
61 | scanf("%d%d", &n, &d);
| ~~~~~^~~~~~~~~~~~~~~~
catinatree.cpp:64:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
64 | scanf("%d", &a);
| ~~~~~^~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
25 ms |
47200 KB |
Output is correct |
| 2 |
Incorrect |
27 ms |
47176 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
25 ms |
47200 KB |
Output is correct |
| 2 |
Incorrect |
27 ms |
47176 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
25 ms |
47200 KB |
Output is correct |
| 2 |
Incorrect |
27 ms |
47176 KB |
Output isn't correct |
| 3 |
Halted |
0 ms |
0 KB |
- |
