제출 #572312

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
572312		600Mihnea	밀림 점프 (APIO21_jumps)	C++17	21 / 100	4049 ms	19768 KiB

jumps

#include "jumps.h"
#include <bits/stdc++.h>

using namespace std;


const int N = 200000 + 7;
const int K = 20;
const int inf = (int) 1e9 + 7;
int n, a[N], lft[N], rgh[N], position[N];
int rmq[K][N], lg2[N];

int getmax(int l, int r) {
  assert(1 <= l && l <= r && r <= n);
  int k = lg2[r - l + 1];
  return max(rmq[k][l], rmq[k][r - (1 << k) + 1]);
}

void init(int nn, vector<int> hh) {
  n = nn;

  assert(n == (int) hh.size());

  for (int i = 1; i <= n; i++) {
    a[i] = hh[i - 1];
    position[a[i]] = i;

    rmq[0][i] = a[i];
  }

  for (int i = 2; i <= n; i++) {
    lg2[i] = 1 + lg2[i / 2];
  }

  for (int k = 1; (1 << k) <= n; k++) {
    for (int i = 1; i + (1 << k) - 1 <= n; i++) {
      rmq[k][i] = max(rmq[k - 1][i], rmq[k - 1][i + (1 << (k - 1))]);
    }
  }


  {
    vector<int> stk;
    for (int i = 1; i <= n; i++) {
      while (!stk.empty() && a[stk.back()] <= a[i]) stk.pop_back();
      if (!stk.empty()) lft[i] = stk.back(); else lft[i] = 0;
      stk.push_back(i);
    }
  }
  {
    vector<int> stk;
    for (int i = n; i >= 1; i--) {
      while (!stk.empty() && a[stk.back()] <= a[i]) stk.pop_back();
      if (!stk.empty()) rgh[i] = stk.back(); else rgh[i] = 0;
      stk.push_back(i);
    }
  }
  for (int i = 1; i <= n; i++) {
    if (lft[i]) {
      assert(a[lft[i]] > a[i]);
    }
    if (rgh[i]) {
      assert(a[rgh[i]] > a[i]);
    }
  }
}

int minimum_jumps(int l1, int r1, int l2, int r2) {
  l1++;
  r1++;
  l2++;
  r2++;

  assert(1 <= l1 && l1 <= r1 && r1 < l2 && l2 <= r2 && r2 <= n);

  int ymax = getmax(l2, r2);
  l1 = max(l1, lft[position[ymax]] + 1);

  int sol = inf;

  for (int x = l1; x <= r1; x++) {

    int p = x, cost = 0;
    while (1) {
      cost++;

      int p2 = p;
      if (rgh[p] && l2 <= rgh[p] && rgh[p] <= r2) {
        sol = min(sol, cost);
        break;
      }

      if (lft[p] && a[lft[p]] <= ymax && a[lft[p]] > a[p2]) p2 = lft[p];
      if (rgh[p] && a[rgh[p]] <= ymax && a[rgh[p]] > a[p2]) p2 = rgh[p];

      assert(p != p2);
      p = p2;
    }
  }

  if (sol == inf) {
    sol = -1;
  }

  return sol;
}

• Subtask 1: 0 / 4
• Subtask 2: 8 / 8
• Subtask 3: 13 / 13
• Subtask 4: 0 / 12
• Subtask 5: 0 / 23
• Subtask 6: 0 / 21
• Subtask 7: 0 / 19