Submission #415021

#	Time	Username	Problem	Language	Result	Execution time	Memory
415021		schse	Mechanical Doll (IOI18_doll)	C++17	10 / 100	86 ms	18636 KiB

doll

#include "doll.h"
#ifndef EVAL
#include "grader.cpp"
#endif
#include <bits/stdc++.h>
using namespace std;

struct node
{
  vector<int> follow;
  set<int> options;
};

vector<node> g;

vector<int> C, X, Y;
int mx = 2;
vector<bool> tree((1 << 18) + 5, true);

void rec(int index, int value)
{
  if (index >= mx / 2)
  {
    if (tree[index])
      X[index - 1] = value;
    else
      Y[index - 1] = value;
  }
  else if (tree[index])
    rec(index * 2, value);
  else
    rec(index * 2 + 1, value);
  tree[index] = !tree[index];
}

void create_circuit(int M, std::vector<int> A)
{

  int N = A.size();
  while (N >= (mx = mx * 2) * 2)
    ;

  { // built graph
    g.resize(M + 1);
    g[0].follow.push_back(A[0]);
    g[0].options.insert(A[0]);
    for (int i = 1; i < N; i++)
    {
      g[A[i - 1]].follow.push_back(A[i]);
      g[A[i - 1]].options.insert(A[i]);
    }
    g[A[N - 1]].follow.push_back(0);
    g[A[N - 1]].options.insert(0);
  }
  int toeliminate = N - mx;
  toeliminate++;

  C.resize(M + 1);
  fill(C.begin(), C.end(), -1);

  // eliminate unnecessary

  for (int i = 0; i < M + 1; i++)
  {
    if (g[i].options.size() == 1 && g[i].follow.back() != 0)
    {
      toeliminate -= g[i].follow.size();
      C[i] = g[i].follow.back();
    }

    else if (g[i].options.empty())
      C[i] = 0;
  }

  assert(toeliminate <= 0);

  X.resize(mx - 1, -1);
  Y.resize(mx - 1, -1);
  for (int i = 1; i < mx / 2; i++)
  {
    X[i - 1] = i * -2;
    Y[i - 1] = i * -2 - 1;
  }
  for (int i = 1; i < N; i++)
  {
    if (C[A[i - 1]] == -1)
      rec(1, A[i]);
  }
  Y[Y.size() - 1] = 0;
  answer(C, X, Y);
}

• Subtask 1: 0 / 2
• Subtask 2: 0 / 4
• Subtask 3: 0 / 10
• Subtask 4: 10 / 10
• Subtask 5: 0 / 18
• Subtask 6: 0 / 56