Submission #30991

#	Time	Username	Problem	Language	Result	Execution time	Memory
30991		szawinis	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	100 / 100	143 ms	9596 KiB

skyscraper

#include <bits/stdc++.h>
using namespace std;
const int MAX = (3e4)+1, INF = 1e9;

int n, m, s, e, a[MAX], b[MAX], d[MAX];
vector<int> ls[MAX];
int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cin >> n >> m;
	for(int i = 0; i < n; i++) d[i] = INF;
	for(int i = 0; i < m; i++) {
		cin >> a[i] >> b[i];
		ls[a[i]].push_back(b[i]);
		if(i == 0) s = a[i];
		if(i == 1) e = a[i];
	}
	for(int i = 0; i < n; i++) {
		sort(ls[i].begin(), ls[i].end());
		ls[i].resize(distance(ls[i].begin(), unique(ls[i].begin(), ls[i].end())));
	}
	priority_queue<pair<int,int>, vector<pair<int,int> >, greater<pair<int,int> > > pq;
	pq.emplace(d[s] = 0, s);
	while(!pq.empty()) {
		int dd, u; tie(dd, u) = pq.top();
		pq.pop();
		if(d[u] < dd) continue;
		for(int p: ls[u]) {
			for(int i = 1; u + i*p < n; i++) {
				if(d[u] + i < d[u + i*p]) pq.emplace(d[u + i*p] = d[u] + i, u + i*p);
				if(binary_search(ls[u + i*p].begin(), ls[u + i*p].end(), p)) break;
			}
			for(int i = 1; u - i*p >= 0; i++) {
				if(d[u] + i < d[u - i*p]) pq.emplace(d[u - i*p] = d[u] + i, u - i*p);
				if(binary_search(ls[u - i*p].begin(), ls[u - i*p].end(), p)) break;
			}
		}
	}
	cout << (d[e] == INF ? -1 : d[e]);
}

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