Submission #916256

#	Time	Username	Problem	Language	Result	Execution time	Memory
916256		adhityamv	Rainforest Jumps (APIO21_jumps)	C++17	23 / 100	4046 ms	83356 KiB

jumps

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define mp make_pair
#define pii pair<int,int>
#define fi first
#define se second
const int N=200000;
const int ln=20;
int n;
vector<int> seg[4*N];
int big[N][ln];
int small[N][ln];
int l[N];
int r[N];
int h[N];
int ind[N+1];
void Build(int l,int r,int pos){
    if(l==r){
        seg[pos].push_back(h[l]);
        return;
    }
    int m=(l+r)/2;
    Build(l,m,2*pos);
    Build(m+1,r,2*pos+1);
    merge(seg[2*pos].begin(),seg[2*pos].end(),seg[2*pos+1].begin(),seg[2*pos+1].end(),back_inserter(seg[pos]));
}
int Query(int l,int r,int pos,int ql,int qr,int ub){
    if(ql>r || qr<l) return -1;
    if(ql<=l && qr>=r){
        auto it=lower_bound(seg[pos].begin(),seg[pos].end(),ub);
        if(it==seg[pos].begin()) return -1;
        it--;
        return (*it);
    }
    int m=(l+r)/2;
    return max(Query(l,m,2*pos,ql,qr,ub),Query(m+1,r,2*pos+1,ql,qr,ub));
}
void init(int nn,vector<int> hh){
    n=nn;
    for(int i=0;i<n;i++)  h[i]=hh[i];;
    for(int i=0;i<n;i++) ind[h[i]]=i;
    stack<int> fl;
    fl.push(-1);
    for(int i=0;i<n;i++){
        while(fl.top()!=-1 && h[fl.top()]<h[i]) fl.pop();
        l[i]=fl.top();
        fl.push(i);
    }
    stack<int> fr;
    fr.push(-1);
    for(int i=n-1;i>=0;i--){
        while(fr.top()!=-1 && h[fr.top()]<h[i]) fr.pop();
        r[i]=fr.top();
        fr.push(i);
    }
    for(int i=0;i<n;i++){
        if(l[i]==-1){
            big[i][0]=small[i][0]=r[i];
            continue;
        }
        if(r[i]==-1){
            big[i][0]=small[i][0]=l[i];
            continue;
        }
        if(h[l[i]]>h[r[i]]){
            big[i][0]=l[i];
            small[i][0]=r[i];
        } else{
            big[i][0]=r[i];
            small[i][0]=l[i];
        }
    }
    for(int j=1;j<ln;j++){
        for(int i=0;i<n;i++){
            if(big[i][j-1]==-1) big[i][j]=-1;
            else big[i][j]=big[big[i][j-1]][j-1];
            if(small[i][j-1]==-1) small[i][j]=-1;
            else small[i][j]=small[small[i][j-1]][j-1];
        }
    }
    Build(0,n-1,1);
}
int check(int s,int e){
    if(h[s]>=h[e]) return -1;
    int ans=0;
    for(int j=ln-1;j>=0;j--){
        if(big[s][j]!=-1 && h[big[s][j]]<h[e]){
            s=big[s][j];
            ans+=(1<<j);
        }
    }
    if(e==l[s] || e==r[s]) return ans+1;
    for(int j=ln-1;j>=0;j--){
        if(small[s][j]!=-1 && h[small[s][j]]<h[e]){
            s=small[s][j];
            ans+=(1<<j);
        }
    }
    if(e==l[s] || e==r[s]) return ans+1;
    return -1;
}
int minimum_jumps(int a,int b,int c,int d){
    int ans=N;
    for(int j=c;j<=d;j++){
        int s=ind[Query(0,n-1,1,a,b,h[j])];
        int cans=check(s,j);
        if(cans!=-1) ans=min(cans,ans);
    }
    
    if(ans==N) ans=-1;
    return ans;
}

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