Submission #656487

#	Time	Username	Problem	Language	Result	Execution time	Memory
656487		tamthegod	Biochips (IZhO12_biochips)	C++17	100 / 100	521 ms	408772 KiB

biochips

// Make the best become better
// No room for laziness
#include<bits/stdc++.h>

#define pb push_back
#define fi first
#define se second
using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int maxN = 2e5 + 5;
const int maxM = 505;
const int mod = 1e9 + 7;
const ll oo = 1e18;
int n, m;
vector<int> adj[maxN];
int a[maxN];
int root;
int f[maxN][maxM];
int sz[maxN];
int tmp[maxM];
void ReadInput()
{
    cin >> n >> m;
    for(int i=1; i<=n; i++)
    {
        int p;
        cin >> p >> a[i];
        if(!p) root = i;
        else
        {
            adj[p].pb(i);
            adj[i].pb(p);
        }
    }
}
void dfs(int u, int par)
{
   // cout << u << " ";
    f[u][0] = 0;
    sz[u] = 1;
    for(int v : adj[u])
    {
        if(v == par) continue;
        dfs(v, u);
        fill(tmp, tmp + m + 1, 0);
        for(int i=0; i<=min(m, sz[u]); i++)
            for(int j=0; j<=min(m - i, sz[v]); j++)
                tmp[i + j] = max(tmp[i + j], f[u][i] + f[v][j]);
        sz[u] += sz[v];
        for(int i=1; i<=min(m, sz[u]); i++)
            f[u][i] = tmp[i];
    }
    f[u][1] = max(f[u][1], a[u]);
}
void Solve()
{
    dfs(root, 0);
    cout << f[root][m];
}
int32_t main()
{
   // freopen("x.inp", "r", stdin);
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    ReadInput();
    Solve();
}

• Subtask 1: 100 / 100