# include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 2;
int n, m, rt, a[N], tin[N], tout[N], timer, cur, pre;
long long dp[2][N], x[N];
vector <int> g[N];
void dfs1(int v){
tin[v] = ++ timer;
for(int to : g[v]){
dfs1(to);
}
tout[v] = timer;
}
void dfs(int v){
for(int to : g[v]){
dfs(to);
}
dp[cur][tout[v]] = max(dp[cur][tout[v]], dp[pre][tin[v] - 1] + x[v]);
}
int main(){
cin >> n >> m;
for(int i = 1; i <= n; i ++){
int p;
cin >> p >> x[i];
if(!p)
rt = i;
else {
g[p].push_back(i);
}
}
dfs1(rt);
for(int i = 1; i <= n; i ++){
dp[1][tout[i]] = max(x[i], dp[1][tout[i]]);
}
for(int i = 2; i <= m; i ++){
cur = i % 2;
pre = cur ^ 1;
for(int j = 1; j <= n; j ++)
dp[pre][j] = max(dp[pre][j - 1], dp[pre][j]);
for(int j = 0; j <= n + 1; j ++)
dp[cur][j] = -1e18;
dfs(rt);
}
long long ans = 0;
for(int i = 1; i <= n; i ++)
ans = max(ans, dp[m % 2][i]);
cout << ans << endl;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
5112 KB |
Output is correct |
2 |
Correct |
5 ms |
5116 KB |
Output is correct |
3 |
Correct |
6 ms |
5116 KB |
Output is correct |
4 |
Correct |
26 ms |
5560 KB |
Output is correct |
5 |
Correct |
27 ms |
5608 KB |
Output is correct |
6 |
Correct |
34 ms |
5636 KB |
Output is correct |
7 |
Correct |
901 ms |
11012 KB |
Output is correct |
8 |
Correct |
862 ms |
11076 KB |
Output is correct |
9 |
Correct |
1046 ms |
11972 KB |
Output is correct |
10 |
Execution timed out |
2061 ms |
12508 KB |
Time limit exceeded |