Submission #414534

#	Time	Username	Problem	Language	Result	Execution time	Memory
414534		Carmel_Ab1	Rainforest Jumps (APIO21_jumps)	C++17	37 / 100	4033 ms	15168 KiB

jumps

#include <bits/stdc++.h>
#include "jumps.h"

//#include "stub.cpp"

using namespace std;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int,int> pi;
#define all(x) x.begin(),x.end()
#define pb push_back

vvi g;
int n=-1;
bool line=1;

void init(int N, vi h){
    n=N;
    g.resize(n);
    for(int i=0; i<n; i++)
        line&=h[i]==i+1;

    vi nxt(n,-1),prv(n,-1);

    stack<int>s;

    for(int i=0; i<n; i++){
        while(s.size() && h[i]>h[s.top()]){
            nxt[s.top()]=i;
            s.pop();
        }
        s.push(i);
    }
    while(s.size())
        s.pop();
    for(int i=n-1; 0<=i ;i--){
        while(s.size() && h[i]>h[s.top()]){
            prv[s.top()]=i;
            s.pop();
        }
        s.push(i);
    }

    for(int i=0; i<n;i ++){
        if(nxt[i]!=-1)
            g[i].pb(nxt[i]);
        if(prv[i]!=-1)
            g[i].pb(prv[i]);
    }
}
int minimum_jumps(int A, int B, int C, int D){
    if(line)
        return C-B;
    vector<bool>vis(n);
    queue<pi>q;

    for(int i=A; i<=B; i++)
        q.push({0,i});

    while(q.size()){
        pi cur=q.front();
        q.pop();

        int src=cur.second,dst=cur.first;
        if(C<= src && src<=D)
            return dst;
        if(vis[src])continue;
        vis[src]=1;
        for(int nbr:g[src])
            if(!vis[nbr])
                q.push({dst+1,nbr});
    }
    return -1;
}

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