Submission #585366

#	Time	Username	Problem	Language	Result	Execution time	Memory
585366		GusterGoose27	Jakarta Skyscrapers (APIO15_skyscraper)	C++11	100 / 100	171 ms	65044 KiB

skyscraper

#include <bits/stdc++.h>
 
using namespace std;
 
typedef pair<int, int> pii;
 
const int MAXN = 3e4;
const int inf = 1e9;
vector<pii> edges[MAXN];
unordered_set<int> at[MAXN];
int n, m;
int dist[MAXN];
 
void dijkstra(int s) {
	fill(dist, dist+n, inf);
	dist[s] = 0;
	priority_queue<pii, vector<pii>, greater<pii>> pq;
	pq.push(pii(0, s));
	while (!pq.empty()) {
		pii p = pq.top();
		pq.pop();
		int cur = p.second;
		if (dist[cur] < p.first) continue;
		for (pii e: edges[cur]) {
			if (dist[cur]+e.second < dist[e.first]) {
				dist[e.first] = dist[cur]+e.second;
				pq.push(pii(dist[e.first], e.first));
			}
		}
	}
}
 
int main() {
	ios_base::sync_with_stdio(false); cin.tie(NULL);
	cin >> n >> m;
	int posf;
	int poss;
	for (int i = 0; i < m; i++) {
		int x, y; cin >> x >> y;
		if (i == 1) posf = x;
		if (i == 0) poss = x;
		at[x].insert(y);
	}
	for (int i = n-1; i >= 0; i--) {
		for (int p: at[i]) {
			for (int j = i+p; j < n; j += p) {
				edges[i].push_back(pii(j, (j-i)/p));
				if (at[j].find(p) != at[j].end()) break;
			}
		}
	}
	for (int i = 0; i < n; i++) {
		for (int p: at[i]) {
			for (int j = i-p; j >= 0; j -= p) {
				edges[i].push_back(pii(j, (i-j)/p));
				if (at[j].find(p) != at[j].end()) break;
			}
		}
	}
	dijkstra(poss);
	cout << ((dist[posf] == inf) ? (-1) : dist[posf]) << "\n";
	return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:60:10: warning: 'poss' may be used uninitialized in this function [-Wmaybe-uninitialized]
   60 |  dijkstra(poss);
      |  ~~~~~~~~^~~~~~
skyscraper.cpp:61:21: warning: 'posf' may be used uninitialized in this function [-Wmaybe-uninitialized]
   61 |  cout << ((dist[posf] == inf) ? (-1) : dist[posf]) << "\n";
      |            ~~~~~~~~~^

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