Submission #1175004

#	Time	Username	Problem	Language	Result	Execution time	Memory
1175004		Johan	Rainforest Jumps (APIO21_jumps)	C++20	33 / 100	4006 ms	19296 KiB

jumps

#include "jumps.h"
#include "bits/stdc++.h"
using namespace std;

const int MAX = 3e5 + 6;
const int LOG = 25;
const int inf = 1e9;
const int mod = 1e9 + 7;
const int block = 333;
// mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int st[MAX * 4];
queue < int > q;
vector < int > d(MAX, -1);
vector < vector < int > > adj(MAX);
void fix(){
  d.assign(MAX, -1);
  while(q.size()) q.pop();
}
void bfs(){
  while(q.size()){
    int v = q.front();
    q.pop();
    for(auto u : adj[v]){
      if(d[u] == -1){
        q.push(u);
        d[u] = d[v] + 1;
      }
    }
  }
}
void upd(int v, int l, int r, int pos, int val){
  if(l == r){
    st[v] = val;
    return ;
  }
  int mid = (l + r) >> 1;
  if(mid >= pos)
    upd(v * 2, l, mid, pos, val);
  else
    upd(v * 2 + 1, mid + 1, r, pos, val);
  st[v] = max(st[v * 2], st[v * 2 + 1]);
}
int ask(int v, int l, int r, int ql, int qr){
  if(l > qr || r < ql)
    return -inf;
  if(l >= ql && r <= qr)
    return st[v];
  int mid = (l + r) >> 1;
  return max(ask(v * 2, l, mid, ql, qr), ask(v * 2 + 1, mid + 1, r, ql, qr));
}
void init(int N, vector<int> H) {
  int n = N;
  vector < int > h = H;
  for(int i = 0; i < n; i++)
    upd(1, 0, n - 1, i, h[i]);
  for(int i = 0; i < n; i++){
    int l = i + 1, r = n - 1;
    int best = -1;
    while(r >= l){
      int mid = (l + r) >> 1;
      if(ask(1, 0, n - 1, i + 1, mid) >= h[i]){
        r = mid - 1;
        best = mid;
      }
      else  
        l = mid + 1;
    }
    if(best != -1)
      adj[i].push_back(best);
    l = 0, r = i - 1;
    best = -1;
    while(r >= l){
      int mid = (l + r) >> 1;
      if(ask(1, 0, n - 1, mid, i - 1) >= h[i]){
        l = mid + 1; 
        best = mid;
      }
      else
        r = mid - 1;
    }
    if(best != -1)
      adj[i].push_back(best);
  }
}
int minimum_jumps(int A, int B, int C, int D){
  fix();
  for(int i = A; i <= B; i++){
    d[i] = 0;
    q.push(i);
  }
  bfs();
  int mn = inf;
  for(int i = C; i <= D; i++){
    if(d[i] == -1)  continue;
    mn = min(mn, d[i]);
  }
  return (mn == inf ? -1 : mn);
}
// signed main(){
//   int n, q;
//   cin >> n >> q;
//   vector < int > a(n);
//   for(int i = 0; i < n; i++)
//     cin >> a[i];
//   init(n, a);
//   while(q--){
//     int a, b, c, d;
//     cin >> a >> b >> c >> d;
//     cout << minimum_jumps(a, b, c, d) << endl;
//   }
// }

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