Submission #965509

#	Time	Username	Problem	Language	Result	Execution time	Memory
965509		FEDIKUS	Highway Tolls (IOI18_highway)	C++17	0 / 100	18 ms	5680 KiB

highway

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

using namespace std;
using ll = long long;

const int maxn=90010;

vector<pair<int,int> > g[maxn];
vector<pair<int,int> > g2[maxn];

int uradi(int n,int m,int a,int b,ll bez,int prva,int pocetak,int skoropocetak,vector<int> &u,vector<int> &v){
  queue<int> bfs;
  bfs.push(pocetak);
  vector<bool> posetio(n,0);
  posetio[pocetak]=true;
  for(auto i:g[pocetak]){
    if(i.first!=skoropocetak) posetio[i.first]=true;
  }

  vector<int> redosled;
  vector<int> cross;
  vector<int> intime(n,0);
  int t=0;

  while(!bfs.empty()){
    int node=bfs.front();
    intime[node]=t++;
    bfs.pop();

    for(auto [u,ind]:g[node]){
      if(posetio[u]){
        cross.push_back(ind);  
        continue;
      }
      if(ind<prva) continue;
      posetio[u]=true;
      bfs.push(u);
      redosled.push_back(ind);
    }
  }

  int l=0;
  int r=int(redosled.size())-1; // ?
  int ret=-1;
  while(l<=r){
    int mid=l+(r-l)/2;

    vector<int> w(m,0);
    fill(w.begin(),w.begin()+prva,1);
    for(int i:cross) w[i]=1;
    for(int i=mid;i<int(redosled.size());i++){
      w[redosled[i]]=1;
    }
    if(ask(w)>bez){
      ret=mid;
      l=mid+1;
    }else r=mid-1;
  }

  if(intime[u[redosled[ret]]]>intime[v[redosled[ret]]]){
    return u[redosled[ret]];
  }else return v[redosled[ret]];
}

void find_pair(int n,vector<int> u,vector<int> v,int a,int b) {
  int m=u.size();
  int prva=0;
  int l=1,r=m;
  ll bez=ask(vector<int>(m,0));
  while(l<=r){
    int mid=l+(r-l)/2;
    vector<int> w(m,0);
    fill(w.begin(),w.begin()+mid,1);
    if(ask(w)>bez){
      prva=mid;
      r=mid-1;
    }else l=mid+1;
  }

  prva--;

  for(int i=0;i<m;i++){
    g[u[i]].push_back({v[i],i});
    g[v[i]].push_back({u[i],i});
  }

  int lik1=uradi(n,m,a,b,bez,prva,u[prva],v[prva],u,v);
  int lik2=uradi(n,m,a,b,bez,prva,v[prva],u[prva],u,v);

  //cout<<lik1<<" "<<lik2<<"\n";

  answer(lik1,lik2);
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 7
• Subtask 3: 0 / 6
• Subtask 4: 0 / 33
• Subtask 5: 0 / 18
• Subtask 6: 0 / 31