#include <bits/stdc++.h>
#define fastio ios_base::sync_with_stdio(0), cin.tie(0)
#define fi first
#define se second
#define endl '\n'
#define all(v) (v).begin(), (v).end()
#define compress(v) sort(all(v)), (v).erase(unique(all((v))), v.end())
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using ld = long double;
const int N = 2e5 + 5;
const int M = 500 + 5;
// INFO
int n, m;
int root;
int a[N];
vector<int> adj[N];
// DFS
int out[N], cnt1 = 1;
int invout[N];
int arr[N], cnt2 = 1;
int freq[N], match[N];
// DP
int dp[N][M];
void dfs(int cur, int pv) {
arr[cnt2++] = cur;
for (auto &next : adj[cur]) {
if (next == pv) continue;
dfs(next, cur);
}
arr[cnt2++] = cur;
out[cnt1] = cur;
invout[cur] = cnt1;
cnt1++;
}
int main() {
cin >> n >> m;
for (int i = 1; i <= n; i++) {
int u;
cin >> u >> a[i];
if (u == 0) root = i;
adj[i].push_back(u);
adj[u].push_back(i);
}
dfs(root, 0);
for (int i = 1, p = 0; i <= 2 * n; i++) {
freq[arr[i]]++;
if (freq[arr[i]] == 2) p = arr[i];
else match[arr[i]] = p;
}
memset(dp, -1, sizeof dp);
for (int i = 0; i <= n; i++) dp[i][0] = 0;
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= m; j++) {
dp[i][j] = dp[i - 1][j];
int node = match[out[i]];
int idx = invout[node];
if (dp[idx][j - 1] != -1) {
dp[i][j] = max(dp[i][j], dp[idx][j - 1] + a[out[i]]);
}
}
}
cout << dp[n][m] << endl;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
199 ms |
400384 KB |
Output is correct |
2 |
Correct |
187 ms |
400356 KB |
Output is correct |
3 |
Correct |
195 ms |
400356 KB |
Output is correct |
4 |
Correct |
208 ms |
400960 KB |
Output is correct |
5 |
Correct |
201 ms |
400996 KB |
Output is correct |
6 |
Correct |
212 ms |
401124 KB |
Output is correct |
7 |
Incorrect |
420 ms |
411108 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |