Submission #109589

#	Time	Username	Problem	Language	Result	Execution time	Memory
109589		arman_ferdous	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	57 / 100	1070 ms	73564 KiB

skyscraper

#include <bits/stdc++.h>
using namespace std;

const int N = 30010;
const int oo = 1e8;
using ii = pair<int,int>;

int n, m, st, ft;
vector<int> f[N];
map<int,int> has[N];

int dist[N];
vector<ii> g[N];
priority_queue<ii, vector<ii>, greater<ii> > q;

int main() {
	scanf("%d %d", &n, &m);
	for(int i = 0; i < m; i++) {
		int b, p; scanf("%d %d", &b, &p);
		f[b].push_back(p);

		if(i == 0) st = b;
		else if(i == 1) ft = b;
	}
	for(int i = 0; i < n; i++) {
		sort(f[i].begin(), f[i].end());
		f[i].erase(unique(f[i].begin(),f[i].end()), f[i].end());
		for(int p : f[i]) has[i][p] = 1;
	}

	for(int i = 0; i < n; i++) {
		for(int p : f[i]) {
			for(int x = i + p, c = 1; x < n; x += p, c++) {
				g[i].push_back({c, x});
				if(has[x][p]) break;
			}
			for(int x = i - p, c = 1; x >= 0; x -= p, c++) {
				g[i].push_back({c, x});
				if(has[x][p]) break;
			}
		}
	}

	for(int i = 0; i < n; i++) dist[i] = oo;
	q.push({0,st});
	dist[st] = 0;
	while(!q.empty()) {
		auto U = q.top(); q.pop();
		int cw = U.first, u = U.second;
		for(auto e : g[u]) {
			if(dist[e.second] > cw + e.first) {
				dist[e.second] = cw + e.first;
				q.push({cw + e.first, e.second});
			}
		}
	}
	if(dist[ft] == oo) puts("-1");
	else printf("%d\n", dist[ft]);
	return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:17:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &n, &m);
  ~~~~~^~~~~~~~~~~~~~~~~
skyscraper.cpp:19:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   int b, p; scanf("%d %d", &b, &p);
             ~~~~~^~~~~~~~~~~~~~~~~

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