Submission #1210979

#	Time	Username	Problem	Language	Result	Execution time	Memory
1210979		hyakup	Overtaking (IOI23_overtaking)	C++20	0 / 100	1 ms	328 KiB

overtaking

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

using ll = long long;

ll tn;
ll l, n, m;

vector<int> stations;
struct Line{
  ll a, b, id; Line( ll a = 0, ll b = 0, ll id = 0 ) : a(a), b(b), id(id) {}
  bool operator < ( Line l ){
    if( b == l.b ) return a > l.a;
    return b > l.b;
  }

  ll calc( ll x ){ return a*x + b; }
};

vector<Line> bus;

void init(int L, int N, vector<ll> T, vector<int> W, int X, int M, vector<int> S)
{
  tn = X;
  l = L;
  n = N;
  m = M;

  for( int i = 0; i < n; i++ ) bus.push_back(Line( W[i], T[i], i ));

  stations = S;
}


ll arrival_time(ll y){

  vector<vector<int>> adj(n + 1);
  vector<ll> t(n + 1), marc(n + 1);

  vector<Line> lines;
  for( auto x : bus ) lines.push_back(x);
  lines.push_back(Line(tn, y, n));

  function<void(int, int)> dfs = [&]( int cur, ll val ){
    t[cur] = val;
    marc[cur] = true;
    for( int viz : adj[cur] ) dfs( viz, val );
  };

  for( int pos = 1; pos < (int)stations.size(); pos++ ){
    fill( marc.begin(), marc.end(), 0);
    sort( lines.begin(), lines.end() );
    adj.clear();
    adj.resize(n + 1);
    stack<pair<ll, int>> pilha;

    ll delta = stations[pos] - stations[pos - 1];
    for( auto x : lines ){
      t[x.id] = x.calc(delta);
      while( !pilha.empty() && pilha.top().first <= t[x.id] ){
        adj[x.id].push_back(pilha.top().second );
        pilha.pop();
      }

      pilha.push({ t[x.id], x.id });
    }

    reverse( lines.begin(), lines.end() );
    for( auto x : lines ) if( !marc[x.id] ) dfs( x.id, t[x.id] );

    lines.clear();
    for( auto x : bus ) lines.push_back(Line(x.a, t[x.id], x.id));
    lines.push_back(Line(tn, t[n], n ));
  }

  return t[n];
}

• Subtask 0: 0 / 0
• Subtask 1: 0 / 9
• Subtask 2: 0 / 10
• Subtask 3: 0 / 20
• Subtask 4: 0 / 26
• Subtask 5: 0 / 35