Submission #443942

#	Time	Username	Problem	Language	Result	Execution time	Memory
443942		peijar	Comparing Plants (IOI20_plants)	C++17	19 / 100	4048 ms	10216 KiB

plants

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

/*
 * Si h[i] < h[i+1], alors r[i+1] <= r[i]
 * Si h[i] > h[i+1] alors r[i+1] >= r[i]
 * Donc si on a r[i] != r[i+1] on peut comparer r[i] et r[i+1] !
 * r[i+1] > r[i] => h[i+1] < h[i]
 * r[i+1] < r[i] => h[i+1] > h[i]
 */

const int MAXN = 2e5;

int k;
int nbPlusGrands[MAXN], cntEq[MAXN][2];
int ordre[MAXN];
int nbDevant[MAXN];
int nbPlantes;

int disCircle(int x, int y) {
  if (x < y)
    return y - x;
  return nbPlantes - x + y;
}

void init(int _k, vector<int> r) {
  k = _k;
  nbPlantes = r.size();
  for (int iPlante = 0; iPlante < nbPlantes; ++iPlante) {
    nbPlusGrands[iPlante] = r[iPlante];
  }

  if (k == 2) {

    for (int i = nbPlantes - 1; i >= 0; --i) {
      if (i == nbPlantes - 1) {
        int x = 1;
        while (x < nbPlantes and nbPlusGrands[x - 1] == nbPlusGrands[i])
          x++;
        cntEq[i][nbPlusGrands[i]] = x;
      } else {
        cntEq[i][nbPlusGrands[i]] = 1 + cntEq[i + 1][nbPlusGrands[i]];
      }
    }
  } else if (2 * k > nbPlantes) {
    for (int i = 0; i < nbPlantes; ++i)
      nbDevant[i] = k - 1, ordre[i] = -1;
    for (int iOrdre = 0; iOrdre < nbPlantes; ++iOrdre) {
      vector<int> possibles;
      for (int iPlante = 0; iPlante < nbPlantes; ++iPlante)
        if (ordre[iPlante] == -1 and nbDevant[iPlante] == nbPlusGrands[iPlante])
          possibles.push_back(iPlante);
      while (possibles.size() > 1) {
        int x = possibles.back();
        possibles.pop_back();
        int y = possibles.back();
        possibles.pop_back();
        if (disCircle(x, y) < k)
          possibles.push_back(x);
        else
          possibles.push_back(y);
      }
      int x = possibles.back();
      ordre[x] = iOrdre;
      for (int iPlante = 0; iPlante < nbPlantes; ++iPlante)
        if (disCircle(iPlante, x) < k and ordre[iPlante] == -1)
          nbDevant[iPlante]--;
    }
  }
}

int compare_plants(int x, int y) {
  if (k == 2) {
    bool allSame1[2] = {true, true};
    bool allSame2[2] = {true, true};
    int dis1 = disCircle(x, y);
    int dis2 = disCircle(y, x);
    for (int b = 0; b < 2; ++b) {
      allSame1[b] = cntEq[x][b] >= dis1;
      allSame2[b] = cntEq[y][b] >= dis2;
    }
    /*for (int i = x; i != y; i = (i + 1 == nbPlantes ? 0 : i + 1))
      allSame1[!nbPlusGrands[i]] = false;
    for (int i = y; i != x; i = (i + 1 == nbPlantes ? 0 : i + 1))
      allSame2[!nbPlusGrands[i]] = false;*/
    if (allSame1[0] or allSame2[1])
      return 1;
    else if (allSame1[1] or allSame2[0])
      return -1;
    return 0;
  } else if (2 * k > nbPlantes) {
    return (ordre[x] < ordre[y] ? -1 : 1);
  }
  return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 14 / 14
• Subtask 3: 0 / 13
• Subtask 4: 0 / 17
• Subtask 5: 0 / 11
• Subtask 6: 0 / 15
• Subtask 7: 0 / 25