#include <bits/stdc++.h>
using namespace std;
const int NM = 2e5, MM = 500, inf = 1e9+7;
int N, M, p[NM+5], x[NM+5], timer = 0, tin[NM+5], tout[NM+5], tour[NM+5];
vector <int> son[NM+5];
int dp[NM+5][MM+5];
void dfs_euler_tour(int u){
tin[u] = ++timer;
tour[timer] = u;
for (int v : son[u]){
dfs_euler_tour(v);
}
tout[u] = timer;
}
int main(){
// freopen("BIOCHIPS.inp", "r", stdin);
// freopen("BIOCHIPS.out", "w", stdout);
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> N >> M;
for (int i = 1; i <= N; i++){
cin >> p[i] >> x[i];
son[p[i]].push_back(i);
}
dfs_euler_tour(0);
for (int i = 1; i <= M; i++) dp[N+1][i] = -inf;
for (int i = N; i >= 1; i--){
int u = tour[i];
for (int j = 1; j <= M; j++){
dp[i][j] = -inf;
if (dp[tout[u]+1][j-1] != -inf) dp[i][j] = max(dp[i][j], dp[tout[u]+1][j-1]+x[u]);
if (dp[i+1][j] != -inf) dp[i][j] = max(dp[i][j], dp[i+1][j]);
}
}
cout << dp[1][M];
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
8536 KB |
Output is correct |
2 |
Correct |
2 ms |
8536 KB |
Output is correct |
3 |
Correct |
2 ms |
10680 KB |
Output is correct |
4 |
Correct |
8 ms |
27484 KB |
Output is correct |
5 |
Correct |
8 ms |
29532 KB |
Output is correct |
6 |
Correct |
8 ms |
29364 KB |
Output is correct |
7 |
Correct |
152 ms |
302256 KB |
Output is correct |
8 |
Correct |
155 ms |
302588 KB |
Output is correct |
9 |
Correct |
202 ms |
368100 KB |
Output is correct |
10 |
Correct |
260 ms |
405328 KB |
Output is correct |