Submission #986864

#	Time	Username	Problem	Language	Result	Execution time	Memory
986864		mimi	Harbingers (CEOI09_harbingers)	C++17	70 / 100	1048 ms	30724 KiB

harbingers

#include <iostream>
#include <vector>
#include <stack>
#include <algorithm>
#define ff first
#define ss second
#define pp push_back
#define all(x) (x).begin(),(x).end()
using namespace std;
using ll = long long;
using ld = long double;
using pii = pair <ll,ll>;
const char el ='\n';
const char sp = ' ';
const ll maxn = 1e5+5;
ll n,cnt=1,sz;
vector <pii> adj[maxn];
pii a[maxn];
ll dp[maxn],h[maxn];

struct previous
{
    ll sz,pos,val;
    ll cur,pos1;
    ld val1;
};
previous mark[maxn];

struct CHT
{
    ll n,sz=0,cur=1;
    ll a[maxn],b[maxn];
    ll line [maxn];
    ld poll [maxn];

    CHT(){
        poll[0]=-1e18;}

    ld llersect (ll x, ll y){
        return (ld)1.0 * (b[x]-b[y])/(a[y]-a[x]);}

    void add(ll i, ll u)
    {
        mark[u].sz=sz;
        mark[u].cur=cur;
        while(sz>0)
        {
            if(a[line[sz-1]]==a[i])
            {
                if(b[line[sz-1]]<=b[i])    break;
                else
                {
                    --sz;
                    if(sz>0)   --cur;
                }
            }
            else
            {
                if(sz<2)   break;
                if(llersect(i,line[sz-1])<llersect(i,line[sz-2]))
                {
                    --sz;
                    if(sz>0)   --cur;
                }
                else    break;
            }
        }
        if(sz==0 or a[line[sz-1]]!=a[i])
        {
            if(sz>0)
            {
                mark[u].val1=poll[cur];
                poll[cur] = llersect(line[sz-1],i);
                mark[u].pos1=cur;
                ++cur;
            }
            mark[u].pos=sz;
            mark[u].val=line[sz];
            line[sz]=i;
            ++sz;
        }
    }

    void undo(ll u)
    {
        sz=mark[u].sz;
        cur=mark[u].cur;
        line[mark[u].pos]=mark[u].val;
        poll[mark[u].pos1]=mark[u].val1;
    }

    ll gt(ll x)
    {
        ll id=upper_bound(poll,poll+cur,x)-poll-1;
        return a[line[id]]*x+b[line[id]];
    }

};
CHT f;

void DFS(ll u, ll v)
{
    for(pii i:adj[u])
    {
        if(i.ff==v)  continue;
        h[i.ff]=h[u]+i.ss;
        DFS(i.ff,u);
    }
}

void DFS1(ll u, ll v)
{
    if(u!=1)
    {
        dp[u]=a[u].ss*h[u]+a[u].ff+f.gt(a[u].ss);
        f.a[cnt]=-h[u];
        f.b[cnt]=dp[u];
        f.add(cnt,u);
        ++cnt;
    }
    for(pii i:adj[u])
    {
        if(i.ff==v)  continue;
        DFS1(i.ff,u);
    }
    f.undo(u);
}

void input()
{
    cin>>n;
    for(ll i=1,u,v,s;i<n;++i)
    {
        cin>>u>>v>>s;
        adj[u].pp({v,s});
        adj[v].pp({u,s});
    }
    for(ll i=2,u,v;i<=n;++i)
    {
        cin>>u>>v;
        a[i]={u,v};
    }
    f.a[0]=0;
    f.b[0]=0;
    f.add(0,0);
    DFS(1,0);
    DFS1(1,0);
    for(ll i=2;i<=n;++i)   cout<<dp[i]<<sp;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    input();
    return 0;
}

• Subtask 1: 70 / 100