제출 #1037434

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1037434		aaaaaarroz	통행료 (IOI18_highway)	C++17	51 / 100	172 ms	262144 KiB

highway

#include <bits/stdc++.h>	
#include "highway.h"
using namespace std;
typedef long long ll;
int edgeCnt;
vector<vector<pair<int, int>>> adj;
vector<pair<int, pair<int, int>>> edges;
void find_distances(int index, int last, int dist){
  dist += 1;
  for (auto node : adj[index]){
    if (node.first == last) continue;
    edges.push_back({dist, node});
    find_distances(node.first, index, dist);
  }
}
int find_S(ll dist){
  find_distances(0, 0, 0);
  sort(edges.begin(), edges.end());
  int l = 0, r = edgeCnt - 1;
  while (l < r){
    int c = (l + r + 1) / 2;
    vector<int> w(edgeCnt);
    for (int i = c; i <= r; i++)
      w[edges[i].second.second] = 1;

    ll cur_dist = ask(w);
    if (cur_dist == dist)
      r = c - 1;
    else
      l = c;
  }
  return edges[l].second.first;
}
int bfs_dist;
vector<pair<int, int>> sus_edges;
void find_sus_edges(int index, int last, int dist){
  dist += 1;
  for (auto node : adj[index]){
    if (node.first == last) continue;
    if (dist == bfs_dist)
      sus_edges.push_back(node);
    else
      find_sus_edges(node.first, index, dist);
  }
}
int find_T(int root, ll dist){
  find_sus_edges(root, root, 0);
  int l = 0, r = sus_edges.size() - 1;
  while (l < r){
    int c = (l + r + 1) / 2;
    vector<int> w(edgeCnt);
    for (int i = c; i <= r; i++)
      w[sus_edges[i].second] = 1;

    ll cur_dist = ask(w);
    if (cur_dist == dist)
      r = c - 1;
    else
      l = c;
  }
  return sus_edges[l].first;
}
void find_pair(int N, vector<int> U, vector<int> V, int A, int B){
  edgeCnt = U.size();
  adj = vector<vector<pair<int, int>>>(N);
  for (int i = 0; i < edgeCnt; i++){
    adj[U[i]].push_back({V[i], i});
    adj[V[i]].push_back({U[i], i});
  }
  ll dist = ask(vector<int>(edgeCnt));
  bfs_dist = dist / A;
  int S = find_S(dist);
  int T = find_T(S, dist);
  answer(S, T);
}

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