Submission #998507

#	Time	Username	Problem	Language	Result	Execution time	Memory
998507		Neco_arc	Harbingers (CEOI09_harbingers)	C++17	90 / 100	74 ms	34388 KiB

harbingers

#include <bits/stdc++.h>
//#include <bits/debug.hpp>

#define ll long long
#define all(x) x.begin(), x.end()
#define Neco "Harbingers"
#define resp(x) sort(all(x)), x.resize(unique(all(x)) - x.begin())
#define getbit(x,i) ((x >> i)&1)
#define _left id * 2, l, mid
#define _right id * 2 + 1, mid + 1, r
#define cntbit(x) __builtin_popcountll(x)
#define fi(i, a, b) for(int i = a; i <= b; i++)
#define fid(i, a, b) for(int i = a; i >= b; i--)
#define maxn (int) 2e5 + 7

using namespace std;

const ll mod = 1e9 + 7; //972663749
const ll base = 911382323;

int n;
vector<pair<int, ll>> edges[maxn];
pair<ll, ll> a[maxn];
ll h[maxn], dp[maxn];

struct roll {
    pair<ll, ll> val;
    long double x;
    int siz;
};

struct CHT {
    int N = 0;
    pair<ll, ll> P[maxn];
    long double X[maxn];

    long double inter(pair<ll, ll> x, pair<ll, ll> y) {
        return 1. * (y.second - x.second) / (x.first - y.first);
    }

    void Change(roll x) {
        P[N] = x.val, X[N] = x.x;
        N = x.siz;
    }

    void watch() { fi(i, 1, N) cout << P[i].first << " " << P[i].second << '\n'; cout << '\n'; }

    roll Add(pair<ll, ll> p) {
        p.first *= -1, p.second *= -1;
        int oldN = N, vt = 1;

        if(N > 0) {
            int l = 1, r = N;
            while(l <= r) {
                int mid = (l + r) >> 1;
                if(inter(p, P[mid]) < X[mid]) r = mid - 1;
                else l = mid + 1;
            }
            vt = l;
        }

        roll x = {P[vt], X[vt], oldN};

        N = vt;
        P[N] = p;
        X[N] = N == 1 ? -1e18 : inter(p, P[N - 1]);

        return x;
    }

    ll get(ll x) {
        if(!N) return 1e18;
        int it = upper_bound(X + 1, X + 1 + N, x) - X - 1;
        return -(P[it].first * x + P[it].second);
    }
} Cht;

void dfs(int u, int par) {

    if(u != 1) dp[u] = h[u] * a[u].second + a[u].first + Cht.get(a[u].second);
    roll x = Cht.Add({ -h[u], dp[u] });

    for(auto [v, w] : edges[u]) if(v != par) {
        h[v] = h[u] + w;
        dfs(v, u);
    }

    Cht.Change(x);
}

void solve()
{

     cin >> n;
     fi(i, 1, n - 1) {
        int x, y, w; cin >> x >> y >> w;
        edges[x].push_back({y, w});
        edges[y].push_back({x, w});
    }
    fi(i, 2, n) cin >> a[i].first >> a[i].second;

    dfs(1, 0);
    fi(i, 2, n) cout << dp[i] << " ";

}


int main()
{

    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    if(fopen(Neco".inp", "r")) {
        freopen(Neco".inp", "r", stdin);
        freopen(Neco".out", "w", stdout);
    }


    int nTest = 1;
//    cin >> nTest;


    while(nTest--)
    {
        solve();
    }


    return 0;
}

Compilation message (stderr)

harbingers.cpp: In function 'int main()':
harbingers.cpp:116:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  116 |         freopen(Neco".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
harbingers.cpp:117:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  117 |         freopen(Neco".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 90 / 100