Submission #880674

#	Time	Username	Problem	Language	Result	Execution time	Memory
880674		DylanSmith	Harbingers (CEOI09_harbingers)	C++17	50 / 100	70 ms	16328 KiB

harbingers

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

#define pb push_back
#define sz(x) (int)x.size()
#define all(x) begin(x),end(x)
#define lb(x,y) lower_bound(all(x),y)-begin(x)

mt19937 rng;

struct Line {
    mutable ll k, m, p;
    bool operator<(const Line& o) const { return k < o.k; }
    bool operator<(ll x) const { return p < x; }
};

struct LineContainer : multiset<Line, less<>> {
    // (for doubles, use inf = 1/.0, div(a,b) = a/b)
    static const ll inf = LLONG_MAX;
    ll div(ll a, ll b) { // floored division
        return a / b - ((a ^ b) < 0 && a % b); }
    bool isect(iterator x, iterator y) {
        if (y == end()) return x->p = inf, 0;
        if (x->k == y->k) x->p = x->m > y->m ? inf : -inf;
        else x->p = div(y->m - x->m, x->k - y->k);
        return x->p >= y->p;
    }
    void add(ll k, ll m) {
        auto z = insert({k, m, 0}), y = z++, x = y;
        while (isect(y, z)) z = erase(z);
        if (x != begin() && isect(--x, y)) isect(x, y = erase(y));
        while ((y = x) != begin() && (--x)->p >= y->p)
            isect(x, erase(y));
    }
    ll query(ll x) {
        assert(!empty());
        auto l = *lower_bound(x);
        return l.k * x + l.m;
    }
};

vector<vector<pair<int, int>>> adj;
LineContainer lc;
vector<ll> res;
vector<int> s, v;
vector<bool> vis;
void dfs(int u, int p) {
    vis[u] = true;
    if (u > 0) {
        res[u] = -lc.query(v[u]) + s[u] + (ll)v[u] * p;
        lc.add(p, -res[u]);
    }
    for (auto &edge : adj[u]) {
        int v = edge.first, k = edge.second;
        if (vis[v]) continue;
        //int t = lc.getTime();
        dfs(v, p + k);
        //lc.setTime(t);
    }
}

void solve() {
    int N; cin >> N;
    adj = vector<vector<pair<int, int>>>(N);
    for (int i = 0; i < N - 1; i++) {
        int u, v, k; cin >> u >> v >> k; u--; v--;
        adj[u].pb({v, k});
        adj[v].pb({u, k});
    }
    s = vector<int>(N);
    v = vector<int>(N);
    for (int i = 1; i < sz(s); i++) cin >> s[i] >> v[i];
    lc.add(0, 0);
    res = vector<ll>(N);
    vis = vector<bool>(N, 0);
    dfs(0, 0);
    for (int i = 1; i < sz(res); i++) {
        cout << res[i] << (i == sz(res) - 1 ? "\n" : " ");
    }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    rng = mt19937(chrono::steady_clock::now().time_since_epoch().count());

    solve();
    /*int N = 200000;
    cout << N << "\n";
    for (int i = 1; i < N; i++) {
        int p = rng() % i;
        cout << (p + 1) << " " << (i + 1) << " " << (rng() % 1000000) << "\n";
    }
    for (int i = 0; i < N; i++) {
        cout << (rng() % 1000000) << " " << (rng() % 1000000) << "\n";
    }*/

    return 0;
}

• Subtask 1: 50 / 100