Submission #565633

#	Time	Username	Problem	Language	Result	Execution time	Memory
565633		MurotY	Rainforest Jumps (APIO21_jumps)	C++14	37 / 100	4037 ms	21564 KiB

jumps

#include "jumps.h"
#include <bits/stdc++.h>
#define ll long long
using namespace std;
const int N=2*1e5+7;
vector <int> a;
vector <int> g[N];
bool u[N], u1[N];
int dp[2006][2006];
bool ok=1;
int n;
void init(int N, std::vector<int> H) {
    n=N;
    a=H;
    for (int i=0;i<n-1;i++){
        if (a[i] > a[i+1]) {
            ok=0;
            break;
        }
    }
    if (!ok){
    vector <int> v;
    for (int i=n-1;i>=0;i--){
        while (!v.empty() && a[i] > a[v.back()]) v.pop_back();
        if (!v.empty()) g[i].push_back(v.back());
        v.push_back(i);
    }
    v.clear();
    for (int i=0;i<n;i++){
        while (!v.empty() && a[i] > a[v.back()]) v.pop_back();
        if (!v.empty()) g[i].push_back(v.back());
        v.push_back(i);
    }
    if (n <= 2000){
    for (int i=0;i<n;i++){
        for (int j=0;j<n;j++) dp[i][j]=1e9;
        queue <int> q;
        q.push(i);
        dp[i][i]=0;
        while (!q.empty()){
            int x1=q.front();
            q.pop();
            for (auto l:g[x1]){
                if (dp[i][l] > dp[i][x1]+1){
                    dp[i][l]=dp[i][x1]+1;
                    q.push(l);
                }
            }
        }
    }
    }
    }
}

int minimum_jumps(int A, int B, int C, int D) {

    if (ok) return C-B;
    int ans=1e9;
    if (n <= 2000){
        for (int i=A;i<=B;i++){
            for (int j=C;j<=D;j++){
                ans=min(ans, dp[i][j]);
            }
        }
        if (ans == 1e9) ans=-1;
        return ans;
    }
    queue <int> q;
    int d[N];
    for (int i=0;i<n;i++) d[i]=1e9, q.push(i);
    for (int i=A;i<=B;i++) q.push(i), d[i]=0;
    while (!q.empty()){
        int x=q.front();
        q.pop();
        for (auto l:g[x]){
            if (d[l] > d[x]+1) {
                d[l]=d[x]+1;
                q.push(l);
            }
        }
    }
    for (int i=C;i<=D;i++) ans=min(ans, d[i]);
    if (ans == 1e9) ans=-1;
    return ans;
}

• 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