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Submission #100278

# Submission time Handle Problem Language Result Execution time Memory
100278 2019-03-10T08:18:30 Z tugushka Highway Tolls (IOI18_highway) C++14
51 / 100
 282 ms 11948 KB 
#include<bits/stdc++.h>
#include "highway.h"
#define mp make_pair
#define pb push_back
using namespace std;

using pii = pair < int, int >;

vector < vector < pii > > to;
vector < pii > edg, ans;
vector<int> w;
int n, m, A, B;
long long L;

void bfs( int start, int startParent){
  bool used[n+1];
  memset( used, 0, sizeof(used) );
  ans.clear();
  queue < int > q;
  q.push( start );
  used[start] = 1;
  if( startParent != -1 ) used[startParent] = 1;

  while( !q.empty() ){
    int sz = q.size();
    while(sz--){
      int u = q.front();
      q.pop();
      for( pii v : to[u] ){
        if( used[v.first] ) continue;
        q.push( v.first );
        used[v.first] = 1;
        ans.push_back( mp( v.second, v.first ) );
      }
    }
  }
}

int findEnd( int start, int startParent ){
  bfs( start, startParent );

  fill( w.begin(), w.end(), 0 );
  L = ask( w );

  /*
    	cerr << "############\n";
    	cerr << "start : "<< start << ' ' << startParent << endl;
    	for(int i = 0 ; i < ans.size() ; i++){
    		cerr << ans[i].second << ' ' << ans[i].first << endl;
    	}*/

  if( ans.empty() ) return start;

  // cerr << L << endl;

  long long now;
  int l = 0, r = ans.size()-1;
  while( l+1 < r ){
    int mid = (l+r)>>1;

    fill( w.begin(), w.end(), 0 );
    for(int i = mid ; i <= r ; i++){
      w[ans[i].first] = 1;
    }

    now = ask( w );

    // cerr << l << ' ' << r << " : " << mid << ' ' << now << endl;

    if( now > L ) l = mid;
    else r = mid-1;
  }

  // cerr << l << ' ' << r << endl;

  if( l != r ){
    fill( w.begin(), w.end(), 0 );
    w[ ans[l+1].first ] = 1;
    now = ask( w );
    if( now > L ) return ans[l+1].second;

    fill( w.begin(), w.end(), 0 );
    w[ ans[l].first ] = 1;
    now = ask( w );
    if( now > L ) return ans[l].second;

    return start;
  }

  fill( w.begin(), w.end(), 0 );
  w[ ans[l].first ] = 1;
  now = ask( w );
  if( now > L ) return ans[l].second;

  return start;
}

int findEdge( int start ){
  bfs( start, -1 );

  fill( w.begin(), w.end(), 0 );
  L = ask( w );

  long long now;
  int l = 0, r = ans.size()-1;
  while( l+1 < r ){
    int mid = (l+r)>>1;

    fill( w.begin(), w.end(), 0 );
    for(int i = mid ; i <= r ; i++){
      w[ans[i].first] = 1;
    }

    now = ask( w );

    // cerr << l << ' ' << r << " : " << mid << ' ' << now << endl;

    if( now > L ) l = mid;
    else r = mid-1;
  }

  if( l != r ){
    fill( w.begin(), w.end(), 0 );
    w[ ans[l].first ] = 1;
    now = ask( w );
    if( now > L ) return ans[l].first;

    fill( w.begin(), w.end(), 0 );
    w[ ans[l+1].first ] = 1;
    now = ask( w );
    if( now > L ) return ans[l+1].first;

    return start;
  }

  return ans[l].first;
}

void find_pair(int N, vector<int> U, vector<int> V, int _A, int _B) {
  n = N; A = _A; B = _B; m = U.size();
  w.resize(m);
  to.resize(n+1);

  for(int i = 0 ; i < m ; i++){
    to[ U[i] ].pb( mp( V[i], i ) );
    to[ V[i] ].pb( mp( U[i], i ) );
    edg.push_back( mp( V[i], U[i] ) );
  }

  int e = findEdge( 0 );
  // cerr << "### " << edg[e].first << ' ' << edg[e].second << endl;

  int s = findEnd( edg[e].first, edg[e].second );
  int t = findEnd( edg[e].second, edg[e].first );

  // cerr << "## " << s << ' ' << t << endl;

  answer( s, t );
}
/*
    4 3 1 3 1 3
    0 1
    0 2
    0 3

    10 9 1 5 3 9
    0 1
    0 2
    2 9
    1 3
    1 4
    1 5
    3 6
    4 7
    4 8

    */

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 248 KB Output is correct
2 Correct 2 ms 308 KB Output is correct
3 Correct 2 ms 248 KB Output is correct
4 Correct 2 ms 248 KB Output is correct
5 Correct 2 ms 248 KB Output is correct
6 Correct 2 ms 376 KB Output is correct
7 Correct 2 ms 376 KB Output is correct
8 Correct 2 ms 376 KB Output is correct
9 Correct 2 ms 248 KB Output is correct
10 Correct 2 ms 248 KB Output is correct
11 Correct 2 ms 376 KB Output is correct
12 Correct 2 ms 248 KB Output is correct

Subtask #2
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 376 KB Output is correct
2 Correct 22 ms 1336 KB Output is correct
3 Correct 196 ms 9848 KB Output is correct
4 Correct 189 ms 9844 KB Output is correct
5 Correct 226 ms 9848 KB Output is correct
6 Correct 199 ms 9872 KB Output is correct
7 Correct 197 ms 9824 KB Output is correct
8 Correct 194 ms 9972 KB Output is correct
9 Correct 193 ms 9840 KB Output is correct
10 Correct 190 ms 9960 KB Output is correct
11 Correct 217 ms 9340 KB Output is correct
12 Correct 210 ms 9340 KB Output is correct
13 Correct 202 ms 9292 KB Output is correct
14 Correct 202 ms 9332 KB Output is correct

Subtask #3
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 1272 KB Output is correct
2 Correct 39 ms 2380 KB Output is correct
3 Correct 56 ms 3232 KB Output is correct
4 Correct 154 ms 9340 KB Output is correct
5 Correct 169 ms 9336 KB Output is correct
6 Correct 166 ms 9340 KB Output is correct
7 Correct 152 ms 9336 KB Output is correct
8 Correct 169 ms 9332 KB Output is correct
9 Correct 164 ms 9332 KB Output is correct

Subtask #4
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 376 KB Output is correct
2 Correct 22 ms 1320 KB Output is correct
3 Correct 144 ms 8028 KB Output is correct
4 Correct 193 ms 9840 KB Output is correct
5 Correct 206 ms 9848 KB Output is correct
6 Correct 195 ms 9864 KB Output is correct
7 Correct 191 ms 9848 KB Output is correct
8 Correct 192 ms 9896 KB Output is correct
9 Correct 191 ms 9852 KB Output is correct
10 Correct 206 ms 9836 KB Output is correct
11 Correct 199 ms 9336 KB Output is correct
12 Correct 229 ms 9340 KB Output is correct
13 Correct 234 ms 9336 KB Output is correct
14 Correct 197 ms 9344 KB Output is correct
15 Correct 188 ms 9844 KB Output is correct
16 Correct 201 ms 9844 KB Output is correct
17 Correct 220 ms 9332 KB Output is correct
18 Correct 222 ms 9516 KB Output is correct
19 Correct 190 ms 9864 KB Output is correct
20 Correct 216 ms 9332 KB Output is correct
21 Correct 146 ms 10200 KB Output is correct
22 Correct 172 ms 10216 KB Output is correct
23 Correct 175 ms 9968 KB Output is correct
24 Correct 179 ms 9972 KB Output is correct
25 Correct 180 ms 9424 KB Output is correct

Subtask #5
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 25 ms 1468 KB Output is correct
2 Correct 24 ms 1428 KB Output is correct
3 Correct 209 ms 10308 KB Output is correct
4 Correct 230 ms 10784 KB Output is correct
5 Incorrect 282 ms 11948 KB Output is incorrect: {s, t} is wrong.
6 Halted 0 ms 0 KB -

Subtask #6
0 / 31.0

# Verdict Execution time Memory Grader output
1 Incorrect 34 ms 1416 KB Output is incorrect: {s, t} is wrong.
2 Halted 0 ms 0 KB -