Submission #444165

#	Time	Username	Problem	Language	Result	Execution time	Memory
444165		peijar	Comparing Plants (IOI20_plants)	C++17	15 / 100	1262 ms	41400 KiB

plants

#include "plants.h"
#include <bits/stdc++.h>
#include <type_traits>
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]
 * 1 : AC
 * 2 : AC
 * 3 : AC
 * 4 : AC
 * 5 : AC
 * 6 : NA
 * 7 : NA
 *
 * If can build graph efficiently then ez !
 */

const int MAXN = 2e5;

int k;
int nbPlusGrands[MAXN], cntEq[MAXN][2];
vector<int> adj[MAXN];
int ordre[MAXN];
int nbDevant[MAXN];
bool reach[301][301];
set<int> alwaysSmaller, alwaysBigger;
int nbPlantes;

struct Seg {
  int nbValeurs;
  vector<int> order;
  vector<int> valeurs;
  vector<int> iDeb, iFin, lazy, minVal;
  const int INF = 1e9;

  Seg(vector<int> _v) : nbValeurs(_v.size()), valeurs(_v) {
    int p = 0;
    while ((1 << p) < nbValeurs)
      ++p;
    int x = 2 * (1 << p) + 1;
    iDeb.resize(x), iFin.resize(x), lazy.resize(x), minVal.resize(x);
    buildTree(1, 0, nbValeurs - 1);
  }

  void pull(int iNoeud) {
    minVal[iNoeud] = min(minVal[2 * iNoeud], minVal[2 * iNoeud + 1]);
  }

  void push(int iNoeud) {
    if (!lazy[iNoeud])
      return;
    minVal[iNoeud] += lazy[iNoeud];
    if (iDeb[iNoeud] < iFin[iNoeud]) {
      lazy[2 * iNoeud] += lazy[iNoeud];
      lazy[2 * iNoeud + 1] += lazy[iNoeud];
    }
    lazy[iNoeud] = 0;
  }

  void buildTree(int iNoeud, int deb, int fin) {
    iDeb[iNoeud] = deb, iFin[iNoeud] = fin;
    if (deb == fin) {
      minVal[iNoeud] = valeurs[deb];
      return;
    }
    buildTree(2 * iNoeud, deb, (deb + fin) / 2);
    buildTree(2 * iNoeud + 1, (deb + fin) / 2 + 1, fin);
    pull(iNoeud);
  }

  int queryMin(int iNoeud, int deb, int fin) {
    push(iNoeud);
    if (deb > iFin[iNoeud] or fin < iDeb[iNoeud])
      return 2 * INF;
    if (iDeb[iNoeud] >= deb and iFin[iNoeud] <= fin)
      return minVal[iNoeud];
    return min(queryMin(2 * iNoeud, deb, fin),
               queryMin(2 * iNoeud + 1, deb, fin));
  }

  void decrement(int iNoeud, int deb, int fin) {
    push(iNoeud);
    if (deb > iFin[iNoeud] or fin < iDeb[iNoeud])
      return;
    if (deb <= iDeb[iNoeud] and iFin[iNoeud] <= fin) {
      lazy[iNoeud]--;
      push(iNoeud);
      return;
    }
    decrement(2 * iNoeud, deb, fin);
    decrement(1 + 2 * iNoeud, deb, fin);
    pull(iNoeud);
  }

  int findFirstZero(int iNoeud, int deb, int fin) {
    push(iNoeud);
    if (minVal[iNoeud] or iDeb[iNoeud] > fin or iFin[iNoeud] < deb)
      return -1;
    if (iDeb[iNoeud] == iFin[iNoeud])
      return iDeb[iNoeud];
    int retLft = findFirstZero(2 * iNoeud, deb, fin);
    if (retLft != -1)
      return retLft;
    return findFirstZero(2 * iNoeud + 1, deb, fin);
  }

  void delVal(int iNoeud, int pos) {
    push(iNoeud);
    if (iDeb[iNoeud] > pos or iFin[iNoeud] < pos)
      return;
    if (iDeb[iNoeud] == iFin[iNoeud]) {
      minVal[iNoeud] = INF;
      return;
    }
    delVal(2 * iNoeud, pos);
    delVal(2 * iNoeud + 1, pos);
    pull(iNoeud);
  }

  int findZeroBefore(int pos) {
    int posAvant = pos - k + 1;
    if (posAvant >= 0)
      return findFirstZero(1, posAvant, pos - 1);
    else {
      posAvant += nbValeurs;
      int ret = findFirstZero(1, posAvant, nbValeurs - 1);
      if (ret == -1 and pos)
        ret = findFirstZero(1, 0, pos - 1);
      return ret;
    }
  }

  void get(int pos) {
    // cout << "EXTRACTING " << pos << endl;
    while (true) {
      int x = findZeroBefore(pos);
      if (x == -1)
        break;
      get(x);
    }
    order.push_back(pos);
    int posAvant = pos - k + 1;
    delVal(1, pos);
    if (pos)
      decrement(1, max(0, posAvant), pos - 1);
    if (posAvant < 0)
      decrement(1, posAvant + nbValeurs, nbValeurs - 1);
    // cout << "EXTRACTED " << pos << endl;
  }

  void getNxt() {
    /*cout << "FINDING NEXT : " << endl;
    for (int i = 0; i < nbValeurs; ++i)
      cout << queryMin(1, i, i) << ' ';
    cout << endl;*/
    int posZero = findFirstZero(1, 0, nbValeurs - 1);
    assert(posZero != -1);
    get(posZero);
  }
};

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];
  }

  Seg segMax(r);
  while ((int)segMax.order.size() < nbPlantes)
    segMax.getNxt();
  for (int i = 0; i < nbPlantes; ++i)
    r[i] = k - 1 - r[i];
  Seg segMin(r);
  while ((int)segMin.order.size() < nbPlantes)
    segMin.getNxt();
  for (int i = 0; i < nbPlantes and segMax.order[i]; ++i)
    alwaysBigger.insert(segMax.order[i]);
  for (int i = 0; i < nbPlantes and segMin.order[i]; ++i)
    alwaysSmaller.insert(segMin.order[i]);

  /*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 {
    Seg seg(r);
    while ((int)seg.order.size() < nbPlantes)
      seg.getNxt();
    for (int i = 0; i < nbPlantes; ++i)
      ordre[seg.order[i]] = nbPlantes - 1 - i;
  }*/
}

int compare_plants(int x, int y) {
  if (alwaysBigger.count(y))
    return -1;
  if (alwaysSmaller.count(y))
    return 1;
  return 0;
  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;
    }
    if (allSame1[0] or allSame2[1])
      return 1;
    else if (allSame1[1] or allSame2[0])
      return -1;
    return 0;
  } else
    return (ordre[x] < ordre[y] ? -1 : 1);
}

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