Submission #1165037

#TimeUsernameProblemLanguageResultExecution timeMemory
1165037baldwin_huangRainforest Jumps (APIO21_jumps)C++20
0 / 100
4005 ms19176 KiB
#include <bits/stdc++.h>

using namespace std;

int n;
const int INF = 1e9;

struct node {
	int left = -1;
	int right = -1;
};

vector<node> nodes;

void init(int N, vector<int> H) {
	n = N;
	nodes = vector<node>(n);

	// Precomputing the left value.
	set<int> heights_l;
	vector<int> last_val_l(n + 1, -1);
	for (int i = 0; i < n; i++) {
		auto it = heights_l.upper_bound(H[i]);
		if (it != heights_l.end()) {
			nodes[i].left = last_val_l[*it];
		}
		heights_l.insert(H[i]);
		last_val_l[H[i]] = i;
	}
	// Precomputing the right values.
	set<int> heights_r;
	vector<int> last_val_r(n + 1, -1);
	for (int i = n - 1; i >= 0; i--) {
		auto it = heights_r.upper_bound(H[i]);
		if (it != heights_r.end()) {
			nodes[i].right = last_val_r[*it];
		}
		heights_r.insert(H[i]);
		last_val_r[H[i]] = i;
	}

	// for (int i = 0; i < n; i++) {
	// 	int left = -1;
	// 	int right = -1;
	// 	for (int j = i - 1; j >= 0; j--) {
	// 		if (H[j] > H[i]) {
	// 			left = j;
	// 			break;
	// 		}
	// 	}
	// 	for (int j = i + 1; j < n; j++) {
	// 		if (H[j] > H[i]) {
	// 			right = j;
	// 			break;
	// 		}
	// 	}
	// 	nodes[i].left = left;
	// 	nodes[i].right = right;
	// }

	return;
}

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

	// Start the BFS

	vector<int> dist(n + 10, INF);
	queue<int> q;

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

	while (!q.empty()) {
		int source = q.front(); q.pop();

		if (nodes[source].left != -1 && dist[nodes[source].left] == INF) {
			q.push(nodes[source].left);
			dist[nodes[source].left] = 1 + dist[source];
		}
		if (nodes[source].right != -1 && dist[nodes[source].right] == INF) {
			q.push(nodes[source].right);
			dist[nodes[source].right] = 1 + dist[source];
		}
	}

	int smallest = INF;
	for (int i = C; i <= D; i++) {
		smallest = min(smallest, dist[i]);
	}

	if (smallest == INF) {
		return -1;
	}
	return smallest;
}
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...