Submission #865241

#	Time	Username	Problem	Language	Result	Execution time	Memory
865241		efedmrlr	Harbingers (CEOI09_harbingers)	C++17	70 / 100	1064 ms	28304 KiB

harbingers

//https://cses.fi/problemset/task/2087/

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

#define int long long int
#define MP make_pair
#define pb push_back
#define REP(i,n) for(int (i) = 0; (i) < (n); (i)++)

#pragma GCC optimize("O1,O2,O3")
void fastio() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
}


const long double EPS = 0.000001;
const int INF = 1e17+500;
const int N = 1e5+5;
const int ALPH = 26;
const int LGN = 25;
const int MOD = 1e9+7;
int n,k;
vector<vector<array<int,2> > > adj;
vector<int> s,v;
vector<int> dp;
vector<int> p, pat;
vector<int> ints;
struct Line {
    int a,b;
    Line() {
        a = 0; b = 0;
    }
    Line(int a, int b) {
        this->a = a;
        this->b = b;
    }
    int eval(int x) {
        return a*x + b;
    }
    long double intersect(Line y) {
        return (long double)(b - y.b) / (long double)(y.a - a);
    }
};

deque<Line> cht;
vector<vector<pair<Line, int> > > upds;

bool comp(int idx, int x) {
    return cht[idx].intersect(cht[idx + 1]) >= x;
}

    
void update(Line nw) {
    upds.pb(vector<pair<Line, int> >());
    while(cht.size() > 1 && cht.front().intersect(cht[1]) >= cht.front().intersect(nw)) {
        upds[upds.size() - 1].pb(MP(cht.front(), 0));
        cht.pop_front();
    }
    upds[upds.size() - 1].pb(MP(nw, 1));
    cht.push_front(nw);
}
void restore_last() {
    while(upds.back().size() > 0) {
        auto cur = upds.back().back();
        if(cur.second) {
            cht.pop_front();
        }  
        else {
            cht.push_front(cur.first);
        }
        upds.back().pop_back();
    }
    upds.pop_back();
}
int query(int x) {
    
    int idx = *lower_bound(ints.begin(), ints.begin() + cht.size() - 1, x, comp);
    return cht[idx].eval(x);
    
}




void dfs(int node) {
    for(auto c : adj[node]) {
        if(c[0] == pat[node]) continue;
        pat[c[0]] = node;
        p[c[0]] = p[node] + c[1];
        dfs(c[0]);
    }
}

void dfs2(int node) {
    update(Line(-p[node], dp[node]));
    for(auto c : adj[node]) {
        
        if(c[0] == pat[node]) continue;
        dp[c[0]] = query(v[c[0]]) + v[c[0]] * p[c[0]] + s[c[0]];
        dfs2(c[0]);
    }
    restore_last();
}

inline void solve() {
    cin >> n;
    cht.clear(); upds.clear();
    adj.resize(n+1, vector<array<int,2> >());
    ints.resize(n);
    iota(ints.begin(), ints.end(), 0);
    for(int i = 0; i<n-1; i++) {
        int u,v,d;
        cin>>u>>v>>d;
        adj[u].pb({v,d});
        adj[v].pb({u,d});
    }
    s.resize(n+1);
    v.resize(n+1);
    for(int i = 2; i<=n; i++) {
        cin>>s[i]>>v[i];
    }
    dp.resize(n+1);
    dp[1] = 0;
    pat.resize(n+1); p.resize(n+1);
    pat[1] = 0;
    p[1] = 0;
    dfs(1);
    dfs2(1);
    for(int i = 2; i<=n; i++) {
        cout<<dp[i]<<" ";
    }
    cout<<"\n";
}
 
signed main() {
    fastio();
    int test = 1;
    //cin>>test;
    while(test--) {
        solve();
    }
    
}

• Subtask 1: 70 / 100