Submission #974283

#	Time	Username	Problem	Language	Result	Execution time	Memory
974283		AlperenT_	Rainforest Jumps (APIO21_jumps)	C++17	100 / 100	1029 ms	69604 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][lg+1];
vector< int> G[maxn] ;
int ch(int l , int r){
  int x = 31 - __builtin_clz(r-l+1) ; 
  return (h[mx[l][x]] > h[mx[r-(1<<x)+1][x]] ? mx[l][x] : mx[r-(1<<x)+1][x]) ;
}
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){
      par2[i][0] = n+1 ;
      id = i ;
      continue ;
    }
    if(R[i] == -1)par2[i][0] =n +1 ;
    else par2[i][0] = R[i] ;
    if(L[i]!=-1 && (R[i] == -1 || h[L[i]] < h[R[i]])){
      G[L[i]].pb(i) ;
      if(R[i] == -1)par[i][0] = L[i] ;
      else par[i][0] = R[i] ;
    }else{
      G[R[i]].pb(i) ;
      if(L[i] == -1)par[i][0] = R[i] ;
      else par[i][0] = L[i] ;
    }
  }
  rep(i , 0 ,lg)par2[n+1][i] = n+1 ;
  dfs(id) ;
  rep(j , 1 ,lg){
    rep(i ,1 ,n){
      par2[i][j] = par2[par2[i][j-1]][j-1] ;
      par[i][j] = par[par[i][j-1]][j-1];
      if(i+(1<<(j-1))>n){
        mx[i][j] = mx[i][j-1] ;
      }else{
        mx[i][j] = (h[mx[i][j-1]] > h[mx[i+(1<<(j-1))][j-1]] ? mx[i][j-1] : mx[i+(1<<(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 && h[par[a][i]] <= h[b]){
      a = par[a][i] ;
      ans += (1<<i);
    }
  }
  ans += dis[a]-dis[b] ;
  return ans;
}
 
 
int minimum_jumps(int A, int B, int C, int D) {
  A++;B++;C++;D++;
  int id = ch(C , D) ;
  A = max(A,  max(0,L[id])+1) ;
  if(B < A)return -1 ;
  int id2 = ch(A, B);int ans = 0 ;
  if(answer(id2 ,id) == inf)return -1 ;
  int x = id2 ;
  per(i , lg , 0){
    if(par2[x][i] < C){
        x =par2[x][i] ;
    }
  }
  x = par2[x][0] ;
  int l = x  ;
  x=id2 ;
  per(i , lg , 0){
    if(par[x][i] != 0 && dis[par[x][i]] > dis[l]){
        x =par[x][i]; 
        ans += (1<<i) ;
    }
  }
  if(par[x][0] != 0 && dis[par[x][0]] >= dis[id]){
    ans++;
    x = par[x][0] ;
    if(!(x >= C && x <= D)){
      ans++;
    }
  }else{
    ans = inf ;
  }
  ans = min(ans, answer(id2 , l));
  return ans ;
}

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