제출 #1224036

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1224036		VMaksimoski008	바이오칩 (IZhO12_biochips)	C++17	90 / 100	476 ms	408216 KiB

biochips

#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 5;

int n, m, root, p[N], a[N], dp[N][505], sub[N], in[N], out[N], timer = 1;
vector<int> g[N];

void dfs(int u, int p) {
    for(int v : g[u]) {
        if(v == p) continue;
        dfs(v, u);
        for(int i=min(m, sub[u]); i>=0; i--)
            for(int j=min(m-i, sub[v]); j>=1; j--)
                dp[u][i+j] = max(dp[u][i+j], dp[u][i] + dp[v][j]);
        sub[u] += sub[v];
    }
    sub[u]++;
    dp[u][1] = max(dp[u][1], a[u]);
}

void dfs2(int u, int p) {
    in[u] = timer++;
    for(int v : g[u]) if(v ^ p) dfs2(v, u);
    out[u] = timer - 1;
}

bool anc(int u, int v) {
    return in[u] <= in[v] && out[v] <= out[u];
}

signed main() {
    cin >> n >> m;
    for(int i=1; i<=n; i++) {
        cin >> p[i] >> a[i];
        if(!p[i]) root = i;
        else {
            g[p[i]].push_back(i);
            g[i].push_back(p[i]);
        }
    }

    //fuck this shit
    if(n <= 20) {
        int ans = 0;
        dfs2(root, root);

        for(int s=0; s<(1<<n); s++) {
            if(__builtin_popcount(s) != m) continue;
            vector<int> u;
            for(int i=0; i<n; i++)
                if(s & (1 << i)) u.push_back(i+1);

            bool ok = 1;
            for(int i=0; i<m; i++)
                for(int j=i+1; j<m; j++)
                    if(anc(u[i], u[j]) || anc(u[j], u[i])) ok = 0;

            if(ok) {
                int res = 0;
                for(int x : u) res += a[x];
                ans = max(ans, res);
            }
        }

        cout << ans << '\n';
        return 0;
    }

    dfs(root, root);
    cout << dp[root][m] << '\n';
}

• Subtask 1: 90 / 100