#include <bits/stdc++.h>
#define task "B"
#define all(v) (v).begin(), (v).end()
#define rep(i, l, r) for (int i = (l); i <= (r); ++i)
#define Rep(i, r, l) for (int i = (r); i >= (l); --i)
#define DB(X) { cerr << #X << " = " << (X) << '\n'; }
#define DB1(A, _) { cerr << #A << "[" << _ << "] = " << (A[_]) << '\n'; }
#define DB2(A, _, __) { cerr << #A << "[" << _ << "][" << __ << "] = " << (A[_][__]) << '\n'; }
#define DB3(A, _, __, ___) { cerr << #A << "[" << _ << "][" << __ << "][" << ___ << "] = " << (A[_][__][___]) << '\n'; }
#define PR(A, l, r) { cerr << '\n'; rep(_, l, r) DB1(A, _); cerr << '\n';}
#define SZ(x) ((int)(x).size())
#define pb push_back
#define eb emplace_back
#define pf push_front
#define F first
#define S second
#define by(x) [](const auto& a, const auto& b) { return a.x < b.x; } // sort(arr, arr + N, by(a));
#define next ___next
#define prev ___prev
#define y1 ___y1
#define left ___left
#define right ___right
#define y0 ___y0
#define div ___div
#define j0 ___j0
#define jn ___jn
using ll = long long;
using ld = long double;
using ull = unsigned long long;
using namespace std;
typedef pair<int, int> ii;
typedef pair<ii, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<ll> vl;
const int N = 2e5 + 2;
int n, K, st[N], eul[N], neu = 0, a[N], dp[N][2];
vi g[N];
void dfs(int u, int p)
{
st[u] = neu;
for (int v : g[u]) if (v != p) dfs(v, u);
eul[++neu] = u;
}
int main()
{
#ifdef HynDuf
freopen(task".in", "r", stdin);
//freopen(task".out", "w", stdout);
#else
ios_base::sync_with_stdio(false); cin.tie(nullptr);
#endif
cin >> n >> K;
rep(i, 1, n)
{
int p;
cin >> p >> a[i];
g[p].eb(i);
}
dfs(g[0][0], 0);
int now = 1, lst = 0;
rep(k, 1, K)
{
swap(now, lst);
rep(i, 0, n) dp[i][now] = -1;
rep(i, 1, n)
{
dp[i][now] = dp[i - 1][now];
if(dp[st[eul[i]]][lst] != -1) dp[i][now] = max(dp[i][now], dp[st[eul[i]]][lst] + a[eul[i]]);
}
}
cout << dp[n][now];
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
4 ms |
4992 KB |
Output is correct |
| 2 |
Correct |
3 ms |
4992 KB |
Output is correct |
| 3 |
Correct |
3 ms |
4992 KB |
Output is correct |
| 4 |
Correct |
8 ms |
5504 KB |
Output is correct |
| 5 |
Correct |
10 ms |
5504 KB |
Output is correct |
| 6 |
Correct |
10 ms |
5504 KB |
Output is correct |
| 7 |
Correct |
251 ms |
10616 KB |
Output is correct |
| 8 |
Correct |
251 ms |
10488 KB |
Output is correct |
| 9 |
Correct |
367 ms |
11000 KB |
Output is correct |
| 10 |
Correct |
499 ms |
11512 KB |
Output is correct |
