Submission #488812

#	Time	Username	Problem	Language	Result	Execution time	Memory
488812		Theo830	Rainforest Jumps (APIO21_jumps)	C++17	0 / 100	1 ms	328 KiB

jumps

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll INF = 1e9+7;
const ll MOD = 998244353;
typedef pair<ll,ll> ii;
#define iii pair<ii,ll>
#define f(i,a,b) for(ll i = a;i < b;i++)
#define pb push_back
#define vll vector<ll>
#define F first
#define S second
#define all(x) (x).begin(), (x).end()
///I hope I will get uprating and don't make mistakes
///I will never stop programming
///sqrt(-1) Love C++
///Please don't hack me
///@TheofanisOrfanou Theo830
///Think different approaches (bs,dp,greedy,graphs,shortest paths,mst)
///Stay Calm
///Look for special cases
///Beware of overflow and array bounds
///Think the problem backwards
///APIO 2021 vc
#include "jumps.h"
vector<vector<ll> >adj;
ll L[200005],R[200005];
vector<int>arr;
ll n;
void init(int N, std::vector<int> H){
    n = N;
    arr = H;
    priority_queue<ii>pq;
    f(i,0,N){
        L[i] = R[i] = INF;
    }
    f(i,0,N){
        while(!pq.empty() && -pq.top().F < H[i]){
            R[pq.top().S] = i;
            pq.pop();
        }
        pq.push(ii(-H[i],i));
    }
    while(!pq.empty()){
        pq.pop();
    }
    for(ll i = N-1;i >= 0;i--){
        while(!pq.empty() && -pq.top().F < H[i]){
            L[pq.top().S] = i;
            pq.pop();
        }
        pq.push(ii(-H[i],i));
    }
    f(i,0,N){
        if(L[i] != INF){
            adj[i].pb(L[i]);
        }
        if(R[i] != INF){
            adj[i].pb(R[i]);
        }
    }
}
int minimum_jumps(int A, int B, int C, int D) {
    ll ans = INF;
    ll dist[n];
    f(i,0,n){
        dist[i] = INF;
    }
    queue<ll>q;
    f(s,A,B+1){
        q.push(s);
        dist[s] = 0;
    }
    while(!q.empty()){
        ll x = q.front();
        q.pop();
        for(auto y:adj[x]){
            if(dist[y] == INF){
                dist[y] = 1 + dist[x];
                q.push(y);
            }
        }
    }
    f(e,C,D+1){
        ans = min(ans,dist[e]);
    }
    if(ans == INF){
        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