제출 #936228

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
936228		VMaksimoski008	Harbingers (CEOI09_harbingers)	C++14	60 / 100	155 ms	15852 KiB

harbingers

#include <bits/stdc++.h>

#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
//#define int long long

using namespace std;

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

const int mod = 1e9 + 7;
const int LOG = 20;
const int maxn = 1e5 + 5;
const double eps = 1e-9;

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

struct LineContainer : multiset<Line, less<> > {
    static const ll INF = LLONG_MAX;

    ll div(ll a, ll b) { return a / b - ((a ^ b) < 0 && a % b); }

    bool intersect(iterator x, iterator y) {
        if(y == end()) {
            x->p = INF;
            return 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 });
        auto y = z++;
        auto x = y;

        while(intersect(y, z)) z = erase(z);

        if(x != begin() && intersect(--x, y))
            intersect(x, y = erase(y));

        while((y = x) != begin() && (--x)->p >= y->p)
            intersect(x, erase(y));
    }

    ll query(ll x) {
        auto l = *lower_bound(x);
        return l.k * x + l.m;
    }
};

int n;
vector<vector<pii> > graph;
pii H[maxn];
vector<int> st;
ll dp[maxn], dist[maxn];

LineContainer lc;

void dfs1(int u, int p) {
    dp[u] = H[u].first + H[u].second * dist[u];

    //H[u].first + H[u].second * dist[u] - (H[u].second * dist[id] - dp[id])
    for(int &id : st)
        dp[u] = min(dp[u], H[u].first + H[u].second * (dist[u] - dist[id]) + dp[id]);

    st.push_back(u);

    for(auto &[v, w] : graph[u]) {
        if(v == p) continue;
        dist[v] = dist[u] + w;
        dfs1(v, u);
    }

    st.pop_back();
}

void dfs2(int u, int p) {
    if(u != 1) {
        dp[u] = H[u].first + H[u].second * dist[u] - lc.query(H[u].second);
        lc.add(dist[u], -dp[u]);
    }

    for(auto &[v, w] : graph[u]) {
        if(v == p) continue;
        dist[v] = dist[u] + w;
        dfs2(v, u);
    }
}

int32_t main() {
    cin >> n;
    graph.resize(n+1);
    for(int i=1; i<=n; i++) dp[i] = 1e18;
    dp[1] = 0;

    for(int i=0; i<n-1; i++) {
        int a, b, w;
        cin >> a >> b >> w;
        graph[a].push_back({ b, w });
        graph[b].push_back({ a, w });
    }

    for(int i=2; i<=n; i++) cin >> H[i].first >> H[i].second;

    if(n <= 2500) {
        dfs1(1, 0);
    } else {
        lc.add(0, 0);
        dfs2(1, 0);
    }

    for(int i=2; i<=n; i++) cout << dp[i] << " ";
    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

harbingers.cpp: In function 'void dfs1(int, int)':
harbingers.cpp:81:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   81 |     for(auto &[v, w] : graph[u]) {
      |               ^
harbingers.cpp: In function 'void dfs2(int, int)':
harbingers.cpp:96:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   96 |     for(auto &[v, w] : graph[u]) {
      |               ^

• Subtask 1: 60 / 100