oj.uz

답안 #1064978

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1064978 2024-08-18T20:43:15 Z hyakup 통행료 (IOI18_highway) C++17
12 / 100
 247 ms 262144 KB 
#include "highway.h"
#include <bits/stdc++.h>
using namespace std;
#define pii pair<int, int>
#define ll long long
#define bug(x) cout << #x << " " << x << endl;

const int maxn = 1e5 + 10;
vector<pii> edges;
vector<int> adj[maxn], pai( maxn ), dist( maxn ), arestas;

pii dfs( int cur, int last ){
  pii resp( 0, cur );
  pai[cur] = last;
  for( auto viz : adj[cur] ) if( viz != last ){
    auto [d, id] = dfs( viz, cur );
    resp = max( resp, pii( d + 1, id ) );
  }
  return resp;
}

void dfsInit( int cur, int last ){
  pai[cur] = last;
  for( int viz : adj[cur] ) if( viz != last ){
    dist[viz] = dist[cur] + 1;
    dfsInit( viz, cur );
  }
}

void marca( int k ){
  for( int i = 0; i < edges.size(); i++ ){
    auto [a, b] = edges[i];
    arestas[i] = (int)(max(dist[a], dist[b]) <= k );
    // bug(i);
    // bug(arestas[i]);
  }
}

void find_pair(int N, vector<int> U, vector<int> V, int A, int B){
  int m = U.size();
  int n = N;
  for( int i = 0; i < m; i++ ){
    adj[U[i]].push_back(V[i]);
    adj[V[i]].push_back(U[i]);
    edges.push_back({ U[i], V[i] });
  }

  // int p1 = dfs( 0, 0 ).second;
  // auto [diam, p2] = dfs( p1, p1 );
  // for( int x = 0; x < diam/2; x++ ) p2 = pai[p2];

  dfsInit( 0, 0 );

  arestas.resize(m);
  ll distancia = ask(arestas)/A;
  // bug(distancia);

  int l = 0, r = n - 1;
  while( l < r ){
    int mid = ( l + r )/2;
    marca( mid );
    ll aux = ask( arestas );
    if( aux == distancia*B ) r = mid;
    else l = mid + 1;
  }
  int nivel_a = r;
  // bug(nivel_a);

  marca( n - 1 );

  vector<int> ids;
  for( int i = 0; i < edges.size(); i++ ){
    auto [a, b] = edges[i];
    if( max( dist[a], dist[b] ) == nivel_a ) ids.push_back(i);
  }

  l = 0, r = ids.size() - 1;
  while( l < r ){
    int mid = ( l + r )/2;
    for( int i = 0; i < ids.size(); i++ ) arestas[ids[i]] = (int)(!( l <= i && i <= mid ));
    if( ask( arestas ) < distancia*B ) r = mid;
    else l = mid + 1;
  }
  auto [x, y] = edges[ids[r]];
  int a = (( dist[x] > dist[y]) ? x : y );

  answer( 0, a );
  //
  // vector<bool> ancestral(N);
  // int aux = a;
  // while( true ){
  //   ancestral[aux] = true;
  //   if( aux == pai[aux] ) break;
  //   aux = pai[aux];
  // }
  //
  // l = max( 0LL, nivel_a - distancia ), r = nivel_a;
  //
  // while( l < r ){
  //   int mid = ( l + r )/2;
  //   marca( mid );
  //   if( ask( arestas ) == distancia*B - 1LL*( nivel_a - mid )*(B - A)) r = mid;
  //   else l = mid + 1;
  // }
  //
  // int nivel_b = r;
  //
  // if( nivel_b == nivel_a - distancia ){
  //   int b = a;
  //   for( int i = 0; i < distancia; i++ ) b = pai[b];
  //   answer( a, b );
  // }
  // else{
  //   ids.clear();
  //   for( int i = 0; i < edges.size(); i++ ){
  //     auto [a, b] = edges[i];
  //     if( !(ancestral[a] && ancestral[b] ) && max( dist[a], dist[b] ) == nivel_b ) ids.push_back(i);
  //   }
  //
  //   marca( n - 1 );
  //   l = 0, r = ids.size();
  //   while( l < r ){
  //     int mid = ( l + r )/2;
  //     for( int i = 0; i < ids.size(); i++ ) arestas[ids[i]] = (int)(!( l <= i && i <= mid ));
  //     if( ask( arestas ) < distancia*B ) r = mid;
  //     else l = mid + 1;
  //   }
  //
  //   int b = (( dist[edges[ids[r]].first] > dist[edges[ids[r]].second]) ?edges[ids[r]].first : edges[ids[r]].second );
  //   answer( a, b );
  // }

}

Compilation message

highway.cpp: In function 'void marca(int)':
highway.cpp:31:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |   for( int i = 0; i < edges.size(); i++ ){
      |                   ~~^~~~~~~~~~~~~~
highway.cpp: In function 'void find_pair(int, std::vector<int>, std::vector<int>, int, int)':
highway.cpp:72:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   72 |   for( int i = 0; i < edges.size(); i++ ){
      |                   ~~^~~~~~~~~~~~~~
highway.cpp:80:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   80 |     for( int i = 0; i < ids.size(); i++ ) arestas[ids[i]] = (int)(!( l <= i && i <= mid ));
      |                     ~~^~~~~~~~~~~~

Subtask #1
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 3416 KB Output is correct
2 Correct 1 ms 3416 KB Output is correct
3 Correct 1 ms 3416 KB Output is correct
4 Correct 2 ms 3416 KB Output is correct
5 Correct 1 ms 3416 KB Output is correct
6 Correct 1 ms 3416 KB Output is correct
7 Correct 2 ms 3416 KB Output is correct
8 Correct 2 ms 3416 KB Output is correct
9 Correct 3 ms 3416 KB Output is correct
10 Correct 1 ms 3416 KB Output is correct
11 Correct 1 ms 3416 KB Output is correct
12 Correct 1 ms 3596 KB Output is correct

Subtask #2
7.0 / 7.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 3416 KB Output is correct
2 Correct 8 ms 4184 KB Output is correct
3 Correct 73 ms 9072 KB Output is correct
4 Correct 83 ms 9664 KB Output is correct
5 Correct 79 ms 9076 KB Output is correct
6 Correct 79 ms 9196 KB Output is correct
7 Correct 76 ms 9012 KB Output is correct
8 Correct 78 ms 9192 KB Output is correct
9 Correct 76 ms 9012 KB Output is correct
10 Correct 72 ms 9064 KB Output is correct
11 Correct 89 ms 9876 KB Output is correct
12 Correct 81 ms 10328 KB Output is correct
13 Correct 80 ms 10452 KB Output is correct
14 Correct 73 ms 9560 KB Output is correct

Subtask #3
0 / 6.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 8 ms 4440 KB Output is incorrect: {s, t} is wrong.
2 Halted 0 ms 0 KB -

Subtask #4
0 / 33.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 2 ms 3416 KB Output is incorrect: {s, t} is wrong.
2 Halted 0 ms 0 KB -

Subtask #5
0 / 18.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 247 ms 262144 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -

Subtask #6
0 / 31.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 223 ms 262144 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -