Submission #907354

#	Time	Username	Problem	Language	Result	Execution time	Memory
907354		yellowtoad	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	57 / 100	121 ms	66984 KiB

skyscraper

#include <iostream>
#include <vector>
#include <queue>
#define f first
#define s second
using namespace std;
 
const short LIM = 174; 
short n, m, st, ed;
unsigned short dist[6000010];
bool vis[6000010], hv[30010];
int cnt, b[30010][180];
pair<short,short> a[30010];
vector<vector<pair<int,unsigned short>>> edge;
deque<int> q;
 
int main() {
	ios::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
	cin >> n >> m;
	cnt = n-1;
	for (short i = 0; i < n; i++) edge.push_back({});
	for (short i = 1; i <= m; i++) {
		cin >> a[i].f >> a[i].s;
		hv[a[i].f] = 1;
	}
	for (short i = 1; i <= m; i++) {
		short u = a[i].f, v = a[i].s;
		if (i == 1) st = u;
		if (i == 2) ed = u;
		if (v <= LIM) {
			if (!b[u][v]) {
				for (int j = u%v; j < n; j += v) {
					b[j][v] = ++cnt;
					edge.push_back({});
					if (hv[j]) edge[cnt].push_back({j,0});
					if (j != u%v) {
						edge[cnt].push_back({cnt-1,1});
						edge[cnt-1].push_back({cnt,1});
					}
				}
			}
			edge[u].push_back({b[u][v],0});
		} else {
			for (int j = u%v; j < n; j += v) {
				++cnt;
				edge.push_back({});
				if (hv[j]) edge[cnt].push_back({j,0});
				if (j == u) edge[u].push_back({cnt,0});
				if (j != u%v) {
					edge[cnt].push_back({cnt-1,1});
					edge[cnt-1].push_back({cnt,1});
				}
			}
		}
	}
	for (int i = 0; i <= cnt; i++) dist[i] = 65535;
	q.push_back(st);
	dist[st] = 0;
	while (q.size()) {
		int u = q.front();
		q.pop_front();
		if (vis[u]) continue;
		vis[u] = 1;
		if (u == ed) {
			cout << dist[ed] << endl;
			return 0;
		}
		for (int i = 0; i < edge[u].size(); i++) {
			if (dist[edge[u][i].f] > dist[u]+edge[u][i].s) {
				dist[edge[u][i].f] = dist[u]+edge[u][i].s;
				if (edge[u][i].s) q.push_back(edge[u][i].f);
				else q.push_front(edge[u][i].f);
			}
		}
	}
	cout << -1 << endl;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:69:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, short unsigned int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   69 |   for (int i = 0; i < edge[u].size(); i++) {
      |                   ~~^~~~~~~~~~~~~~~~

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