Submission #985285

#	Time	Username	Problem	Language	Result	Execution time	Memory
985285		LOLOLO	Paprike (COI18_paprike)	C++17	100 / 100	41 ms	22976 KiB

paprike

#include <bits/stdc++.h>
#define ll long long
using namespace std;
 
#define           f     first
#define           s     second
#define           pb    push_back
#define           ep    emplace
#define           eb    emplace_back
#define           lb    lower_bound
#define           ub    upper_bound
#define       all(x)    x.begin(), x.end()
#define      rall(x)    x.rbegin(), x.rend()
#define   uniquev(v)    sort(all(v)), (v).resize(unique(all(v)) - (v).begin())
#define     mem(f,x)    memset(f , x , sizeof(f))
#define        sz(x)    (int)(x).size()
#define  __lcm(a, b)    (1ll * ((a) / __gcd((a), (b))) * (b))
#define          mxx    *max_element
#define          mnn    *min_element
#define    cntbit(x)    __builtin_popcountll(x)
#define       len(x)    (int)(x.length())
 
const int N = 1e5 + 10;
vector <int> ed[N];
ll n, k, a[N];
pair <ll, ll> dp[N];

void dfs(int u, int v) {
    int ans = 0;
    vector <int> lst;
    for (auto x : ed[u]) { 
        if (x == v)
            continue;

        dfs(x, u);
        ans += dp[x].f;
        lst.pb(dp[x].s);
    }

    int sum = a[u];
    sort(all(lst));

    for (auto x : lst) {
        if (sum + x <= k) {
            sum += x;
            ans++;
        }
    }

    dp[u].f = ans;
    dp[u].s = sum;
}

int main() {
    ios_base::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 a, b;
        cin >> a >> b;
        ed[a].pb(b);
        ed[b].pb(a);
    }

    dfs(1, 1);

    cout << n - dp[1].f - 1 << '\n';
    return 0;
}

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