Submission #982535

#	Time	Username	Problem	Language	Result	Execution time	Memory
982535		vjudge1	Rainforest Jumps (APIO21_jumps)	C++17	37 / 100	4040 ms	16504 KiB

jumps

#include "jumps.h"
#include <bits/stdc++.h>
#include <vector>
using namespace std;
int n, L[200001], R[200001], d[200001];
bool subtask1, u[200001];
vector<int> g[200001];
void init(int N, std::vector<int> H) {
	n = N;
	stack<int> st;
	subtask1 = 1;
	for (int i = 0; i < N; i++) {
		if (H[i] != i + 1) subtask1 = 0;
	}
	for (int i = 0; i < N; i++) {
		while (st.size() && H[st.top()] <= H[i]) st.pop();
		if (st.size()) L[i] = st.top();
		else L[i] = -1;
		st.push(i);
	}
	for (int i = N - 1; i >= 0; i--) {
		while (st.size() && H[st.top()] <= H[i]) st.pop();
		if (st.size()) R[i] = st.top();
		else R[i] = -1;
		st.push(i);
	}
	for (int i = 0; i < N; i++) {
		if (L[i] != -1) g[i].push_back(L[i]);
		if (R[i] != -1) g[i].push_back(R[i]);
	}
}

int minimum_jumps(int A, int B, int C, int D) {
	if (subtask1) return C - B;
	queue<int> q;
	for (int i = 0; i < n; i++) u[i] = 0, d[i] = 0;
	for (int i = A; i <= B; i++) {
		u[i] = 1;
		q.push(i);
	}
	while (q.size()) {
		int x = q.front();
		q.pop();
		for (auto y : g[x]) {
			if (!u[y]) {
				u[y] = 1;
				d[y] = d[x] + 1;
				q.push(y);
			}
		}
	}
	//for (int i = 0; i < n; i++) cout << d[i] << " ";
	//cout << "\n";
	int ans = 1e9;
	for (int i = C; i <= D; i++) if (u[i]) ans = min(ans, d[i]);
	return (ans < 5e8 ? ans : -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