Submission #1123805

#	Time	Username	Problem	Language	Result	Execution time	Memory
1123805		_callmelucian	Harbingers (CEOI09_harbingers)	C++20	100 / 100	132 ms	22540 KiB

harbingers

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

typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pl;
typedef pair<int,int> pii;
typedef tuple<int,int,int> tpl;

#define all(a) a.begin(), a.end()
#define filter(a) a.erase(unique(all(a)), a.end())

struct line {
    ll slope, c;

    line() : slope(0), c(0) {}
    line (ll u, ll v) : slope(u), c(v) {}

    ll calc (ll x) { return slope * x + c; }

    friend ld xSect (line a, line b) {
        return (ld) (b.c - a.c) / (a.slope - b.slope);
    }

    friend bool valid (line a, line b, line c) {
        return xSect(a, b) < xSect(b, c);
    }
};

struct CHT {
    vector<line> hull;
    stack<pair<int,line>> save;
    stack<int> top;

    void push (line cur) {
        if (hull.size() < 2) {
            top.push(hull.size()), save.emplace(hull.size(), cur);
            hull.push_back(cur);
        }
        else {
            int pos = 0;
            for (int mask = 1 << 18; mask; mask >>= 1) {
                int tmp = pos | mask;
                if (tmp <= top.top() && valid(hull[tmp - 1], hull[tmp], cur)) pos |= mask;
            }
            if (pos + 1 == hull.size()) hull.push_back(cur);
            top.push(pos + 1), save.emplace(pos + 1, hull[pos + 1]);
            hull[pos + 1] = cur;
        }
    }

    void rollback() {
        int p; line cur; tie(p, cur) = save.top();
        hull[p] = cur, top.pop(), save.pop();
    }

    ll query (ll x) {
        if (hull.empty()) return LLONG_MAX;
        int ans = 0;
        for (int mask = 1 << 18; mask; mask >>= 1) {
            int tmp = mask | ans;
            if (tmp <= top.top() && xSect(hull[tmp - 1], hull[tmp]) < x) ans |= mask;
        }
        return hull[ans].calc(x);
    }
} hull;

const int mn = 1e5 + 5;
ll dist[mn], dp[mn], speed[mn], warmUp[mn];
vector<pl> adj[mn];

void dfs (int u, int p, ll wp) {
    if (u != p) {
        dist[u] = dist[p] + wp;
        dp[u] = hull.query(speed[u]) + warmUp[u] + speed[u] * dist[u];
    }
    hull.push(line(-dist[u], dp[u]));
    for (pl item : adj[u]) {
        int v; ll w; tie(v, w) = item;
        if (v != p) dfs(v, u, w);
    }
    hull.rollback();
}

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);

    int n; cin >> n;
    for (int i = 1; i < n; i++) {
        int a, b; ll c; cin >> a >> b >> c;
        adj[a].emplace_back(b, c);
        adj[b].emplace_back(a, c);
    }
    for (int i = 2; i <= n; i++) cin >> warmUp[i] >> speed[i];
    dfs(1, 1, 0);

    for (int i = 2; i <= n; i++) cout << dp[i] << " ";

    return 0;
}

• Subtask 1: 100 / 100