Submission #916215

#	Time	Username	Problem	Language	Result	Execution time	Memory
916215		adhityamv	Rainforest Jumps (APIO21_jumps)	C++17	0 / 100	4053 ms	33232 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 big[N][ln];
int small[N][ln];
int l[N];
int r[N];
int h[N];
void init(int n,vector<int> hh){
    for(int i=0;i<n;i++)  (h[i]=hh[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];
        }
    }
}
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);
        }
    }
    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 i=a;i<=b;i++){
        for(int j=c;j<=d;j++){
            int cans=check(i,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: 0 / 23
• Subtask 6: 0 / 21
• Subtask 7: 0 / 19