Submission #532672

#	Time	Username	Problem	Language	Result	Execution time	Memory
532672		DanerZein	Rainforest Jumps (APIO21_jumps)	C++14	48 / 100	2660 ms	86892 KiB

jumps

#include "jumps.h"
#include <bits/stdc++.h>
using namespace std;
typedef vector<int> vi;
const int MAX_N=2e5+10;
const int MAX_P=MAX_N*4;
int st[MAX_P];
int val[MAX_N];
int n;
vector<vi> lo,hi;
void init_tr(int node,int a,int b){
  if(a==b){
    st[node]=val[a];
    return;
  }
  int mid=(a+b)/2,le=2*node+1,ri=2*node+2;
  init_tr(le,a,mid);
  init_tr(ri,mid+1,b);
  st[node]=max(st[le],st[ri]);
}
int query(int node,int a,int b,int l,int r){
  if(b<l || a>r) return 0;
  if(l<=a && r>=b) return st[node];
  int mid=(a+b)/2,le=2*node+1,ri=2*node+2;
  return max(query(le,a,mid,l,r),query(ri,mid+1,b,l,r));
}
int izquier(int x){
  int q=query(0,0,n-1,0,x);
  if(q==val[x]) return -1;
  int l=0,r=x;
  while(r-l>1){
    int mid=(l+r)/2;
    q=query(0,0,n-1,mid,r);
    if(q>val[x])
      l=mid;
    else r=mid;
  }
  return l;
}
int derecha(int x){
  int q=query(0,0,n-1,x,n-1);
  if(q==val[x]) return -1;
  int l=x,r=n-1;
  while(r-l>1){
    int mid=(l+r)/2;
    q=query(0,0,n-1,l,mid);
    if(q>val[x]) r=mid;
    else l=mid;
  }
  return r;
}
int sh[MAX_N][32];
int sl[MAX_N][32];
bool vis[MAX_N];
void low_edge(int u,int p,int he){
  if(he>=1){
    sl[u][0]=p;
    for(int i=1;i<30;i++){
      if((1<<i)>he) break;
      sl[u][i]=sl[sl[u][i-1]][i-1];
    }
  }
  vis[u]=1;
  for(auto &v:lo[u]){
    if(!vis[v] && v!=p){
      low_edge(v,u,he+1);
    }
  }
}
void high_edge(int u,int p,int he){
  if(he>=1){
    sh[u][0]=p;
    for(int i=1;i<30;i++){
      if((1<<i)>he) break;
      sh[u][i]=sh[sh[u][i-1]][i-1];
    }
  }
  vis[u]=1;
  for(auto &v:hi[u]){
    if(!vis[v] && v!=p){
      high_edge(v,u,he+1);
    }
  }
}
int ih[MAX_N],il[MAX_N];
void init(int N, std::vector<int> H) {
  for(int i=0;i<N;i++) val[i]=H[i];
  hi.resize(N+1);
  lo.resize(N+1);
  n=N;
  memset(ih,0,sizeof ih);
  memset(il,0,sizeof il);
  init_tr(0,0,n-1);
  for(int i=0;i<n;i++){
    int l=izquier(i);
    int r=derecha(i);
    if(r!=-1 && l!=-1){
      if(val[r]>val[l]){
	hi[r].push_back(i);
	lo[l].push_back(i);
      }
      else{
	hi[l].push_back(i);
	lo[r].push_back(i);
      }
      ih[i]++; il[i]++;
    }
    else{
      if(l!=-1) lo[l].push_back(i);
      if(r!=-1) lo[r].push_back(i);
      if(l!=-1 || r!=-1) il[i]++;
    }
  }
  memset(vis,0,sizeof vis);
  memset(sl,-1,sizeof sl);
  memset(sh,-1,sizeof sh);
  for(int i=n-1;i>=0;i--){
    if(!il[i]) low_edge(i,i,0);
  }
  memset(vis,0,sizeof vis);
  for(int i=n-1;i>=0;i--){
    if(!ih[i]) high_edge(i,i,0);
  }
}
int jumps(int A,int C){
  int res=0;
  for(int i=29;i>=0;i--){
    if(sh[A][i]!=-1 && val[sh[A][i]]<val[C]){
      A=sh[A][i];
      res+=(1<<i);
    }
  }
  if(val[sh[A][0]]==val[C]) return res+1;
  for(int i=29;i>=0;i--){
    if(sl[A][i]!=-1 && val[sl[A][i]]<val[C]){
      A=sl[A][i];
      res+=(1<<i);
    }
  }
  if(val[sl[A][0]]==val[C]) return res+1;
  return -1;
}
int encontrar(int q,int l,int r){
  if(query(0,0,n-1,l,l)==q) return l;
  while(r-l>1){
    int mid=(l+r)/2;
    if(query(0,0,n-1,l,mid)>=q) r=mid;
    else l=mid;
  }
  return r;
}
int partir(int l,int r,int q){
  int rr=r;
  while(r-l>1){
    int mid=(l+r)/2;
    if(query(0,0,n-1,mid,r)<q) r=mid;
    else l=mid;
  }
  return encontrar(query(0,0,n-1,r,rr),r,rr);
}
int minimum_jumps(int A, int B, int C, int D) {
  if(query(0,0,n-1,A,B)<=val[C]){
    A=encontrar(query(0,0,n-1,A,B),A,B);
    return jumps(A,C);
  }
  else{
    A=partir(A,B,val[C]);
    return jumps(A,C);
  }
}

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