Submission #928735

#	Time	Username	Problem	Language	Result	Execution time	Memory
928735		Regulus	Chase (CEOI17_chase)	C++17	70 / 100	537 ms	17152 KiB

chase

#include <bits/stdc++.h>
#define IO ios::sync_with_stdio(false);cin.tie(0);
#define debug(x) cerr << #x << " = " << (x) << ' '
#define bug(x) cerr << (x) << ' '
#define endl cerr << '\n'
#define all(v) (v).begin(), (v).end()
#define SZ(v) (ll)(v).size()
#define lowbit(x) (x)&-(x)
#define pb emplace_back
#define F first
#define S second
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;

const int N = 1e5+5;
ll a[N], sum[N], ans, m;
vector<ll> g[N];
multiset<ll> st;

inline void dfs(int x, int fa)
{
    sum[x] = 0;
    for (int v : g[x]) if (v != fa) sum[x] += a[v];
    st.insert(sum[x]);

    ll tmp = 0, i = 0;
    for (auto it=st.rbegin(); it != st.rend() && i < m; ++it, ++i)
        tmp += *it;
    ans = max(ans, tmp);

    for (int v : g[x])
    {
        if (v == fa) continue;
        dfs(v, x);
    }
    st.erase(st.find(sum[x]));
}

int main(void)
{ IO
    int n, i;

    cin >> n >> m;
    for (i=1; i <= n; ++i) cin >> a[i];
    for (i=0; i < n-1; ++i)
    {
        int x, y; cin >> x >> y;
        g[x].pb(y), g[y].pb(x);
    }

    for (i=1; i <= n; ++i)
    {
        if (!st.empty()) assert(0);
        dfs(i, 0);
        if (n > 1000) break;
    }

    cout << ans << '\n';

    return 0;
}

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