Submission #89289

#	Time	Username	Problem	Language	Result	Execution time	Memory
89289		lost_breath	Paprike (COI18_paprike)	C++14	100 / 100	118 ms	35472 KiB

paprike

// #define _GLIBCXX_DEBUG
#include <bits/stdc++.h>

#define ll long long
#define ull unsigned ll
#define pb push_back
#define mp make_pair
#define pll pair<ll, ll>
#define pii pair<int, int>
#define ld long double
#define pas(v) cout << #v << ' ' << v << endl
#define all(v) v.begin(), v.end()
#define fi first
#define se second
#define vi vector<ll>
#define vvi vector<vi>
using namespace std;

int main() {
	cout.precision(30);
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int n, k; cin >> n >> k;
    
    vi sp(n);
    for (auto &i : sp) cin >> i;
    
    vvi g(n);
    for (int i = 0; i < n - 1; i++) {
        int a, b; cin >> a >> b;
        a--, b--;
        g[a].pb(b);
        g[b].pb(a);
    }

    function<pll(int, int)> dfs = [&](int v, int p) {
        vi have;
        ll sum = 0;
        ll ret = 0;
        for (auto u : g[v]) {
            if (u == p) continue;
            auto x = dfs(u, v);
            ll s = x.first;
            ll num = x.second;
            ret += num;
            have.pb(s);
            sum += s; 
        }
        sum += sp[v];
        if (sum <= k) return pll{sum, ret};
        sort(all(have));
        while (sum > k) {
            sum -= have.back();
            ret++;
            have.pop_back();
        }

        return pll{sum, ret};
    };

    auto res = dfs(0, -1);
    cout << res.se;

	return 0;	
}

• Subtask 1: 11 / 11
• Subtask 2: 13 / 13
• Subtask 3: 27 / 27
• Subtask 4: 49 / 49