Submission #455662

#	Time	Username	Problem	Language	Result	Execution time	Memory
455662		Hamed5001	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	0 / 100	5 ms	1888 KiB

skyscraper

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

const int mxN = 3e4+10, OO = 0x3f3f3f3f;
int N, M;
vector<int> doges[mxN];
vector<pair<int, int>> adj[mxN];

int dijkstra(int st, int en) {
	vector<int> dist(mxN, OO);
	priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;
	pq.push({0, st});


	while(pq.size()) {
		auto node = pq.top();
		pq.pop();

		if (node.first > dist[node.second])
			continue;

		dist[node.second] = node.first;
		if (node.second == en)
			return node.first;

		for (auto it : adj[node.second]) {
			if (dist[it.second] > node.first + it.first) {
				dist[it.second] = node.first + it.first;
				pq.push({dist[it.second], it.second});
			}
		}
	}
	return -1;
}	

void solve() {
	cin >> N >> M;

	int stB, enB;
	for (int i = 0; i < M; i++) {
		int B, P;
		cin >> B >> P;
		if (!i) stB = B;
		if (!(i-1)) enB = B;
		doges[B].push_back(P);
	}

	for (int i = 0; i < N; i++) {
		for (auto doge : doges[i]) {
			for (int to = i + doge, j = 1; to < N; to += doge, j++){
				adj[i].push_back({j, to});
				if (count(doges[to].begin(), doges[to].end(), doge)) break;
			}
			for (int to = i - doge, j = 1; to >= 0; to -= doge, j++){
				adj[i].push_back({j, to});
				if (count(doges[to].begin(), doges[to].end(), doge)) break;
			}
		}
	}
	cout << dijkstra(stB, enB);
}

int main() {
#ifndef ONLINE_JUDGE
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
#endif
	
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	solve();
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:67:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   67 |  freopen("input.txt", "r", stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:68:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   68 |  freopen("output.txt", "w", stdout);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp: In function 'void solve()':
skyscraper.cpp:62:27: warning: 'enB' may be used uninitialized in this function [-Wmaybe-uninitialized]
   62 |  cout << dijkstra(stB, enB);
      |                           ^
skyscraper.cpp:62:27: warning: 'stB' may be used uninitialized in this function [-Wmaybe-uninitialized]

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