Submission #341823

#	Time	Username	Problem	Language	Result	Execution time	Memory
341823		egod1537	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	100 / 100	136 ms	36588 KiB

skyscraper

#include <bits/stdc++.h>

using namespace std;

const int INF = 0x3f3f3f3f;

typedef pair<int, int> pi;
#define to first
#define cost second
#define pos first
#define range second

struct Q {
	int pos, cost;
};
bool operator<(const Q& a, const Q& b) {
	return a.cost > b.cost;
}

set<pi> V[30001];
set<int> inpos[30001];
int dst[30001];

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0), cout.tie(0);

	memset(dst, INF, sizeof(dst));

	int n, m; cin >> n >> m;
	vector<vector<int>> doge(n);

	int s = 0, e = 0;
	for (int i = 0; i < m; i++)
	{
		int pos, range; cin >> pos >> range;
		if (i == 0) s = pos;
		if (i == 1) e = pos;
		doge[pos].push_back(range);
		inpos[pos].insert(range);
	}
	for (int i = 0; i < n; i++) {
		sort(doge[i].begin(), doge[i].end());
		doge[i].erase(unique(doge[i].begin(), doge[i].end()), doge[i].end());
	}

	for (int pos = 0; pos < n; pos++) {
		set<pi>& nV = V[pos];

		for (int range : doge[pos]) {
			for (int j = pos + range; j < n; j += range) {
				if (inpos[j].size() == 0) continue;
				int dst = j - pos;

				nV.insert({ j, dst / range });
				if (inpos[j].find(range) != inpos[j].end()) break;
			}
			for (int j = pos - range; j >= 0; j -= range) {
				if (inpos[j].size() == 0) continue;
				int dst = pos - j;

				nV.insert({ j, dst / range });
				if (inpos[j].find(range) != inpos[j].end()) break;
			}
		}
	}

	vector<int> vit(n, -1);

	int num = 0;
	priority_queue<Q> pq;
	pq.push({ s, 0 });
	while (!pq.empty()) {
		Q top = pq.top(); pq.pop();

		if (top.pos == e) {
			cout << top.cost;
			return 0;
		}

		for (pi w : V[top.pos]) {
			if (vit[w.to] == num) continue;
			if (dst[w.to] > top.cost + w.cost) {
				dst[w.to] = top.cost + w.cost;
				pq.push({ w.to, dst[w.to] });
			}
			vit[w.to] = num;
		}

		num++;
	}

	cout << -1;

	return 0;
}

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