#include <bits/stdc++.h>
#define fastInp ios_base::sync_with_stdio(0); cin.tie(0);
#define fr first
#define sc second
#define pii pair<int, int>
#define pb push_back
#define all(s) s.begin(), s.end()
#define szof(s) (int)s.size()
using namespace std;
const int MAXN = (int)2e5 + 5;
const int MAXM = (int)500 + 2;
vector <int> g[MAXN];
int cost[MAXN];
int dp[MAXN][MAXM];
int tin[MAXN], tout[MAXN], tiktak = 0;
int n, m;
int root = -1;
vector <int> sub[MAXN];
int DP[505][2];
void calc(int v) {
memset(DP, -1, sizeof(DP));
DP[0][0] = 0;
int tp = 0;
for (int to : sub[v]) {
for (int i = 0; i <= m; i++) {
DP[i][tp ^ 1] = DP[i][tp];
}
for (int cur = 1; cur <= m; cur++) {
if (dp[to][cur] != -1) {
for (int i = m; i >= 0; i--) {
if (DP[i][tp] != -1 && i + cur <= m) {
DP[i + cur][tp ^ 1] = max(DP[i + cur][tp ^ 1], DP[i][tp] + dp[to][cur]);
}
}
}
}
tp ^= 1;
}
}
void dfs(int v, int par) {
if (v != root && szof(g[v]) == 1) { // leaf
dp[v][1] = cost[v];
return;
}
for (int to : g[v]) {
if (to != par) {
dfs(to, v);
sub[v].pb(to);
}
}
dp[v][1] = max(dp[v][1], cost[v]);
for (int to : sub[v]) {
dp[v][1] = max(dp[v][1], dp[to][1]);
}
calc(v);
for (int k = 2; k <= m; k++) {
dp[v][k] = max(DP[k][0], DP[k][1]);
}
sub[v].clear();
}
bool father(int a, int b) {
return (tin[a] <= tin[b] && tout[b] <= tout[a]);
}
signed main() {
fastInp;
cin >> n >> m;
memset(dp, -1, sizeof(dp));
for (int i = 1; i <= n; i++) {
int par, x;
cin >> par >> x;
if (!par) {
root = i;
} else {
g[par].pb(i);
g[i].pb(par);
}
cost[i] = x;
}
dfs(root, -1);
cout << max(0, dp[root][m]);
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
187 ms |
402668 KB |
Output is correct |
2 |
Correct |
187 ms |
402796 KB |
Output is correct |
3 |
Correct |
188 ms |
402668 KB |
Output is correct |
4 |
Correct |
200 ms |
403328 KB |
Output is correct |
5 |
Correct |
202 ms |
403308 KB |
Output is correct |
6 |
Correct |
204 ms |
403308 KB |
Output is correct |
7 |
Correct |
469 ms |
411372 KB |
Output is correct |
8 |
Correct |
462 ms |
411500 KB |
Output is correct |
9 |
Correct |
626 ms |
412652 KB |
Output is correct |
10 |
Correct |
763 ms |
413420 KB |
Output is correct |