제출 #853192

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
853192		thanh913	Chase (CEOI17_chase)	C++14	20 / 100	4091 ms	256828 KiB

chase

#include <bits/stdc++.h>
using namespace std;

#define fi first
#define se second
using ll = long long;

const int N = 1e5+5;

template<class X, class Y>
bool cmax(X &a, const Y &b) {
    return a < b ? a = b, 1 : 0;
}

//--------------------------------------
int n, k, a[N];
vector<int> adj[N];

ll f[N][105][3];
void dfs(int u, int pr) {
    ll s = 0;
    for (auto v : adj[u]) if (v != pr) {
        dfs(v, u);
        s += a[v];
    }

    f[u][0][0] = f[u][1][2] = 0;
    for (auto v : adj[u]) if (v != pr) {
        for (int i = 0; i <= k; i++) {
            cmax(f[u][i][0], max(f[v][i][0], f[v][i][1]));
            cmax(f[u][i][1], f[v][i][2] + a[u]);
            if (i) {
                cmax(f[u][i][2], f[v][i-1][0] + s);
                cmax(f[u][i][2], f[v][i-1][1] + s - a[v]);
                cmax(f[u][i][2], f[v][i-1][2] + s - a[v] + a[u]);
            }
        }
    }
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    cin >> n >> k;
    for (int i = 1; i <= n; i++) cin >> a[i];
    for (int i = 1; i < n; i++) {
        int u, v; cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }

    ll ans = 0;
    for (int root = 1; root <= n; root++) {
        for (int i = 1; i <= n; i++) {
            memset(f[i], -63, sizeof(f[i]));
        }
        dfs(root, root);
        
        for (int i = 0; i <= k; i++) {
            cmax(ans, max({f[root][i][0], f[root][i][1], f[root][i][2]}));
        }
    }
    cout << ans;
}

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