Submission #970749

#	Time	Username	Problem	Language	Result	Execution time	Memory
970749		12345678	Rainforest Jumps (APIO21_jumps)	C++17	33 / 100	4094 ms	16156 KiB

jumps

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

using namespace std;

const int nx=2e5+5, kx=18;

int l[nx], r[nx], n;
vector<int> d[nx];

void init(int N, std::vector<int> H) {
    n=N;
    stack<int> s;
    for (int i=0; i<N; i++) l[i]=r[i]=N;
    for (int i=0; i<N; i++)
    {
        while (!s.empty()&&H[s.top()]<H[i]) s.pop();
        if (!s.empty()) l[i]=s.top(), d[s.top()].push_back(i);
        s.push(i);
    }
    while (!s.empty()) s.pop();
    for (int i=N-1; i>=0; i--)
    {
        while (!s.empty()&&H[s.top()]<H[i]) s.pop();
        if (!s.empty()) r[i]=s.top(), d[s.top()].push_back(i);
        s.push(i);
    }
}

int minimum_jumps(int A, int B, int C, int D) {
    vector<int> mn(n, 1e9);
    queue<int> q;
    for (int i=C; i<=D; i++) mn[i]=0, q.push(i);
    while (!q.empty())
    {
        auto u=q.front();
        q.pop();
        for (auto v:d[u]) if (mn[v]>mn[u]+1) q.push(v), mn[v]=mn[u]+1;
    }
    int res=1e9;
    for (int i=A; i<=B; i++) res=min(res, mn[i]);
    if (res==1e9) return -1;
    return res;
}

• Subtask 1: 0 / 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