Submission #1113138

#	Time	Username	Problem	Language	Result	Execution time	Memory
1113138		ortsac	Rainforest Jumps (APIO21_jumps)	C++17	0 / 100	245 ms	64092 KiB

jumps

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

using namespace std;

#define int long long
#define pii pair<long long, long long>
#define fr first
#define se second

const int MAXLOG = 18;
const int MAXN = 2e5 + 10;
int binl[MAXLOG][MAXN];
int onlyr[MAXLOG][MAXN];
int n;
vector<int> h;
vector<int> l;
vector<int> r;

void init(int32_t N, vector<int32_t> H) {
  n = N;
  h.resize(n);
  for (int i = 0; i < n; i++) h[i] = H[i];
  l.resize(n);
  r.resize(n);
  stack<pii> s;
  for (int i = 0; i < n; i++) {
    while (!s.empty() && (s.top().fr < h[i])) s.pop();
    if (s.empty()) l[i] = -1;
    else l[i] = s.top().se;
    s.push({h[i], i});
  }
  while (!s.empty()) s.pop();
  for (int i = n - 1; i >= 0; i--) {
    while (!s.empty() && (s.top().fr < h[i])) s.pop();
    if (s.empty()) r[i] = -1;
    else r[i] = s.top().se;
    s.push({h[i], i});
  }
  for (int i = 0; i < n; i++) {
    if ((l[i] == -1) && (r[i] == -1)) binl[0][i] = i;
    else if (l[i] == -1) binl[0][i] = r[i];
    else if (r[i] == -1) binl[0][i] = l[i];
    else if (h[l[i]] < h[r[i]]) binl[0][i] = r[i];
    else binl[0][i] = l[i];
    // calc onlyr
    if (r[i] == -1) onlyr[0][i] = i;
    else onlyr[0][i] = r[i];
  }
  for (int j = 1; j < MAXLOG; j++) {
    for (int i = 0; i < n; i++) {
      binl[j][i] = binl[j - 1][binl[j - 1][i]];
      onlyr[j][i] = onlyr[j - 1][onlyr[j - 1][i]];
    }
  }
  //for (int i = 0; i < n; i++) cout << l[i] << " " << r[i] << "\n";
  return;
}

const int INF = 0x3f3f3f3f;

int32_t minimum_jumps(int32_t a, int32_t x, int32_t b, int32_t y) {
  // go from a to b
  if (h[a] > h[b]) return -1;
  int cost = 0;
  for (int i = MAXLOG - 1; i >= 0; i--) {
    if (h[binl[i][a]] < h[b]) {
      //cout << a << " to " << binl[i][a] << "\n";
      a = binl[i][a];
      cost += (1LL << i);
    }
  }
  for (int i = MAXLOG - 1; i >= 0; i--) {
    if (h[onlyr[i][a]] < h[b]) {
      cout << a << " to " << onlyr[i][a] << "\n";
      a = onlyr[i][a];
      cost += (1LL << i);
    }
  }
  if (r[a] != b) return -1;
  return (cost + 1);
}

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