Submission #298734

#	Time	Username	Problem	Language	Result	Execution time	Memory
298734		DanerZein	Highway Tolls (IOI18_highway)	C++14	11 / 100	246 ms	10212 KiB

highway

#include "highway.h"
#include <bits/stdc++.h>
#define MAX 1000000000000000000
using namespace std;
typedef long long ll;
typedef pair<ll,ll> ii;
typedef vector<ii> vi;
vector<vi> G;
vector<int> hl;
ll conc[110];
int isq[110];
ll m,a,b,n;
vector<int> bin;
int ed[90010],vis[90010];
void dijkstra(int x){
  memset(vis,0,sizeof vis);
  queue<int> q;
  int e=0;
  q.push(x);
  while(!q.empty()){
    int u=q.front();
    q.pop();
    vis[u]=1;
    for(auto &v:G[u]){
      if(!vis[v.first]){
	bin.push_back(v.second);
	ed[e]=v.first;
	q.push(v.first);
	e++;
      }
    }
  }
}
void line_graph(int u){
  hl.assign(m,0);
  ll w=ask(hl);
  ll no=w/a;
  int l=0,r=m-1;
  ll aux;
  while(r-l>1){
    int mid=(l+r)/2;
    for(int i=0;i<m;i++){
      if(i<mid) hl[i]=1;
      else hl[i]=0;
    }
    aux=ask(hl);
    if(aux==w) l=mid;
    else r=mid;
  }
  answer(l,l+no);
}
void find_pair(int N, std::vector<int> U, std::vector<int> V, int A, int B) {
  n=N;
  a=A;
  b=B;
  G.resize(N+1);
  for(int i=0;i<U.size();i++){
    int u=U[i],v=V[i];
    G[u].push_back(ii(v,i));
    G[v].push_back(ii(u,i));
  }
  bool sw=0;
  int id=-1;
  for(int i=0;i<N;i++){
    if(G[i].size()>2) sw=1;
    if(G[i].size()==1 and id==-1) id=i;
  }
  m=U.size();
  if(sw==1){
    dijkstra(0);
    hl.assign(m,0);
    /*for(int i=0;i<m;i++){
      cout<<bin[i]<<" ";
    }
    cout<<endl;
    for(int i=0;i<m;i++){
      cout<<ed[i]<<" ";
    }
    cout<<endl;*/
    int l=0,r=m-1,w=ask(hl);
    while(r-l>1){
      int mid=(l+r)/2;
      for(int i=0;i<m;i++){
	if(i<=mid) hl[bin[i]]=0;
	else hl[bin[i]]=1;
      }
      if(ask(hl)==w) r=mid;
      else l=mid;
      /* for(int i=0;i<m;i++) cout<<hl[i]<<" ";
      cout<<endl;*/
    }
    // cout<<r<<" "<<bin[r]<<" "<<ed[r]<<endl;
    answer(0,ed[r]);
  }
  else{
    line_graph(id);
  }
}

Compilation message (stderr)

highway.cpp: In function 'void find_pair(int, std::vector<int>, std::vector<int>, int, int)':
highway.cpp:57:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   57 |   for(int i=0;i<U.size();i++){
      |               ~^~~~~~~~~

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