Submission #1010358

#	Time	Username	Problem	Language	Result	Execution time	Memory
1010358		HappyCapybara	Highway Tolls (IOI18_highway)	C++17	51 / 100	101 ms	11424 KiB

highway

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

#define ll long long

void find_pair(int N, vector<int> U, vector<int> V, int A, int B) {
  int M = U.size();
  vector<vector<pair<int,int>>> g(N);
  for (int i=0; i<M; i++){
    g[U[i]].push_back({V[i], i});
    g[V[i]].push_back({U[i], i});
  }

  vector<int> f(M, 0);
  ll d = ask(f)/A;

  vector<bool> seen(N, false);
  seen[0] = true;
  queue<int> q;
  vector<vector<pair<int,int>>> v;
  for (pair<int,int> next : g[0]){
    vector<pair<int,int>> x;
    x.push_back(next);
    q.push(next.first);
    seen[next.first] = true;
    while (!q.empty()){
      int cur = q.front();
      q.pop();
      for (pair<int,int> neigh : g[cur]){
        if (seen[neigh.first]) continue;
        seen[neigh.first] = true;
        x.push_back(neigh);
        q.push(neigh.first);
      }
    }
    v.push_back(x);
  }

  int l = 0, r = v.size();
  while (l != r-1){
    int m = (l+r)/2;
    vector<int> w(M, 0);
    for (int i=l; i<m; i++){
      for (pair<int,int> p : v[i]) w[p.second] = 1;
    }
    if (ask(w) > d*A) r = m;
    else l = m;
  }

  int br = l;
  l = 0; r = v[br].size();
  while (l != r-1){
    int m = (l+r)/2;
    vector<int> w(M, 0);
    for (int i=m; i<r; i++) w[v[br][i].second] = 1;
    if (ask(w) > d*A) l = m;
    else r = m;
  }

  int S = v[br][l].first;

  vector<int> dist(N, -1);
  q.push(S);
  dist[S] = 0;
  vector<pair<int,int>> pos;
  while (!q.empty()){
    int cur = q.front();
    q.pop();
    for (pair<int,int> next : g[cur]){
      if (dist[next.first] != -1) continue;
      dist[next.first] = dist[cur]+1;
      if (dist[next.first] == d) pos.push_back(next);
      else q.push(next.first);
    }
  }
  l = 0; r = pos.size();
  while (l != r-1){
    int m = (l+r)/2;
    vector<int> w(M, 0);
    for (int i=l; i<m; i++) w[pos[i].second] = 1;
    if (ask(w) > d*A) r = m;
    else l = m;
  }
  answer(S, pos[l].first);
}

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