Submission #481242

#	Time	Username	Problem	Language	Result	Execution time	Memory
481242		CyberSleeper	Race (IOI11_race)	C++14	43 / 100	2431 ms	97732 KiB

race

#include <bits/stdc++.h>
#include "race.h"

#define ll      long long
#define pii     pair<ll, ll>
#define fi      first
#define se      second
#define pb      push_back

using namespace std;

const ll MX=200007, INF=1e9+7;

vector<pii> adj[MX];
map<ll, pii> ada[MX];
ll N, K, ret=INF;

void add(ll i, ll j, ll x){
    if(ada[i].count(j)){
        pii now=ada[i][j];
        if(now.se>x)
            now.se=x;
        if(now.fi>now.se)
            swap(now.fi, now.se);
        ada[i][j]=now;
    }else{
        ada[i][j]={x, INF};
    }
}
void DFS(ll par, ll wpar, ll x){
    ada[x][0]={0, INF};
    for(auto i:adj[x]){
        ll v=i.fi, w=i.se;
        if(v==par)
            continue;
        DFS(x, w, v);
        if(ada[x].size()<ada[v].size())
            swap(ada[x], ada[v]);
        for(auto j:ada[v]){
            ll tot=j.fi, sisa=K-tot;
            pii cnt=j.se;
            if(tot>K)
                continue;
            if(ada[x].count(sisa)){
                ret=min(ret, ada[x][sisa].fi+ada[v][tot].fi);
            }
            add(x, tot, cnt.fi);
            add(x, tot, cnt.se);
        }
    }
    vector<ll> delay;
    vector<pair<ll, pii>> tambah;
    for(auto i=ada[x].rbegin(); i!=ada[x].rend(); i++){
        pair<ll, pii> tmp=*i;

            tmp.se.fi++;
            tmp.se.se++;
            if(tmp.fi+wpar<=K)
                tambah.pb({tmp.fi+wpar, tmp.se});
            delay.pb(tmp.fi);

    }
    for(auto i:delay)
        ada[x].erase(i);
    for(auto i:tambah)
        ada[x][i.fi]=i.se;
    if(ada[x].count(K))
        ret=min(ret, ada[x][K].fi);
}

int best_path(int n, int k, int H[][2], int L[]){
    N=n, K=k;
    for(ll i=0, u, v, w; i<N-1; i++){
        u=H[i][0], v=H[i][1], w=L[i];
        adj[u].pb({v, w});
        adj[v].pb({u, w});
    }
    DFS(0, 0, 0);
    return (ret>=INF?-1:ret);
}

• Subtask 1: 9 / 9
• Subtask 2: 12 / 12
• Subtask 3: 22 / 22
• Subtask 4: 0 / 57