제출 #939159

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
939159		vjudge1	Chase (CEOI17_chase)	C++17	0 / 100	2717 ms	524292 KiB

chase

#include <bits/stdc++.h>

using namespace std;

#define all(x) x.begin(), x.end()
#define ar array
#define pb push_back
#define ln '\n'
#define int long long

using i64 = long long;

template <class F, class _S>
bool chmin(F &u, const _S &v){
    bool flag = false;
    if ( u > v ){
        u = v; flag |= true;
    }
    return flag;
}

template <class F, class _S>
bool chmax(F &u, const _S &v){
    bool flag = false;
    if ( u < v ){
        u = v; flag |= true;
    }
    return flag;
}

#define P pair <int,int>

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int n, k; cin >> n >> k;
    vector <int> a(n);
    for ( auto &u: a ) cin >> u;
    vector <vector<int>> G(n);
    for ( int i = 1; i < n; i++ ){
        int u, v; cin >> u >> v;
        --u, --v;
        G[u].pb(v), G[v].pb(u);
    }
    vector <int> s(n);
    for ( int i = 0; i < n; i++ ){
        for ( auto &v: G[i] ){
            s[i] += a[v];
        }
    }
    vector <vector<pair<int,int>>> L(n, vector <pair<int,int>> (k + 1, {0, -1})), R(n, vector <pair<int,int>> (k + 1, {0, -1}));
    auto dfs = [&](auto dfs, int u, int p) -> void{
        for ( auto &v: G[u] ){
            if ( v == p ) continue;
            dfs(dfs, v, u);
            for ( int j = 0; j <= k; j++ ){
                for ( auto nj: {j, j + 1} ){
                    if ( j > k ) continue;
                    for ( auto nw: {L[v][j], R[v][j]} ){
                        nw.first += (nj - j) * (s[v] - a[u]);
                        if ( L[u][nj].first < nw.first ){
                            swap(R[u][nj], L[u][nj]);
                            L[u][nj] = nw;
                        } else if ( L[u][nj].second == R[u][nj].second || (nw.first > R[u][nj].first && nw.second != L[u][nj].second) ){
                            R[u][nj] = nw;
                        }
                    }
                }
            }
        }
    };
    dfs(dfs, 0, -1);
    int opt = 0;
    for ( int i = 0; i <= k; i++ ){
        chmax(opt, L[0][i].first + s[0]);
    }
    cout << opt;

    cout << '\n';
}

/*
12 2
2 3 3 8 1 5 6 7 8 3 5 4
2 1
2 7
3 4
4 7
7 6
5 6
6 8
6 9
7 10
10 11
10 12
*/

• Subtask 1: 0 / 20
• Subtask 2: 0 / 20
• Subtask 3: 0 / 30
• Subtask 4: 0 / 30