Submission #971378

#	Time	Username	Problem	Language	Result	Execution time	Memory
971378		AlperenT_	Rainforest Jumps (APIO21_jumps)	C++17	8 / 100	4086 ms	54532 KiB

jumps

#include "jumps.h"

#include <vector>
#include <bits/stdc++.h>

#pragma GCC optimize("O3,unroll-loops")
#define pb push_back
#define F first
#define S second 
#define ld long double
#define all(a) a.begin(),a.end()
#define pii pair <int,int>
#define PII pair<pii , pii>
#define sz(v) (int)v.size()
#define rep(i , a , b) for(int i=a;i <= (b);i++)
#define per(i , a , b) for(int i=a;i >= (b);i--)
#define deb(x) cout <<#x << " : " << x << "\n" ;
using namespace std ;
const int maxn = 2e5 + 10 , maxq = 32, inf = 1e9+10 , lg = 19  ,sq = 707 ,mod = 998244353 ;
int mx[maxn][lg+1] , c = 1 , L[maxn] , R[maxn], h[maxn] , dis[maxn] , par[maxn][lg+1] , par2[maxn ];
vector< int> G[maxn] ;

void dfs(int v){
  for(int u : G[v]){
    dis[u] = dis[v] + 1; 
    dfs(u) ;
  }
}

void init(int n, vector<int> H) {
  rep(i ,1 ,n){
    h[i] = H[i-1] ;
    mx[i][0] = i ;
  }
  vector <int> vec;;
  rep(i , 1, n){
    while(sz(vec) && h[vec.back()] < h[i])vec.pop_back() ;
    L[i] = -1 ;
    if(sz(vec)!=0)L[i] = vec.back() ;
    vec.pb(i) ;
  }
  vec.clear() ;
  per(i ,n,1){
    while(sz(vec) && h[vec.back()] < h[i])vec.pop_back() ;
    R[i] = -1 ;
    if(sz(vec)!=0)R[i] = vec.back() ;
    vec.pb(i) ;
  }
  int id =0 ;
  rep(i ,1 ,n){
    if(L[i]+R[i] == -2){
      id = i ;
      continue ;
    }
    if(L[i]!=-1 && (R[i] == -1 || h[L[i]] < h[R[i]])){
      G[L[i]].pb(i) ;par2[i] = L[i] ;
      if(R[i] == -1)par[i][0] = L[i] ;
      else par[i][0] = R[i] ;
    }else{
      G[R[i]].pb(i) ;par2[i] = R[i] ;
      if(L[i] == -1)par[i][0] = R[i] ;
      else par[i][0] = L[i] ;
    }
  }
  dfs(id) ;
  rep(i ,1 ,n){
    rep(j , 1 ,lg){
      par[i][j] = par[par[i][j-1]][j-1];
    }
  }
}

int answer(int a, int b){
  if(L[b] >= a)return inf ;
  int ans =0 ;
  /*
  per(i , lg , 0){
    if(par[a][i] != 0 && dis[par[a][i]] >= dis[b]){
      a = par[a][i] ;
      ans += (1<<i);
    }
  }
  */
  while(a!=b && h[par[a][0]] <= h[b]){
    ans ++ ;
    a= par[a][0] ;
  }
  while(a != b){
    ans ++ ;
    a = par2[a] ;
  }
  return ans;
}

int minimum_jumps(int A, int B, int C, int D) {
  A++;B++;C++;D++;
  int ans = inf ;
  rep(i , A ,B){
    rep(j, C , D){
      ans = min(ans , answer(i , j)) ;
    }
  }
  return (ans == inf ? -1 : ans)  ;
}

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