Submission #400771

#	Time	Username	Problem	Language	Result	Execution time	Memory
400771		BERNARB01	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	36 / 100	247 ms	262148 KiB

skyscraper

#include <bits/stdc++.h>

using namespace std;

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	int n, m;
	cin >> n >> m;
	vector<vector<pair<int, long long>>> g(n);
	int target, start;
	for (int i = 0; i < m; i++) {
		int b, p;
		cin >> b >> p;
		if (i == 0) { 
			start = b;
		}
		if (i == 1) {
			target = b;
		}
		for (int j = b + p, w = 1; j < n; j += p, w++) {
			g[b].emplace_back(j, w);
		}
		for (int j = b - p, w = 1; j >= 0; j -= p, w++) {
			g[b].emplace_back(j, w);
		}
	}
	const long long inf = (long long) 8e18L;
	vector<long long> dist(n, inf);
	priority_queue<pair<long long, int>> s;
	dist[start] = 0;
	s.emplace(0, start);
	while (!s.empty()) {
		long long exp = -s.top().first;
		int u = s.top().second;
		s.pop();
		if (exp != dist[u]) {
			continue;
		}
		if (u == target) {
			break;
		}
		for (auto [v, w] : g[u]) {
			if (dist[u] + w < dist[v]) {
				dist[v] = dist[u] + w;
				s.emplace(-dist[v], v);
			}
		}
	}
	cout << (dist[target] >= inf ? -1 : dist[target]) << '\n';
	return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:31:12: warning: 'start' may be used uninitialized in this function [-Wmaybe-uninitialized]
   31 |  dist[start] = 0;
      |            ^
skyscraper.cpp:40:3: warning: 'target' may be used uninitialized in this function [-Wmaybe-uninitialized]
   40 |   if (u == target) {
      |   ^~

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 14 / 14
• Subtask 4: 0 / 21
• Subtask 5: 0 / 43