Submission #389648

#	Time	Username	Problem	Language	Result	Execution time	Memory
389648		milleniumEeee	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	36 / 100	251 ms	262148 KiB

skyscraper

#include <bits/stdc++.h>
#define fr first
#define sc second
#define pii pair<int, int>
#define pb push_back
#define szof(s) (int)s.size()
#define all(s) s.begin(), s.end()
#define fastInp ios_base::sync_with_stdio(0); cin.tie(0);
#define int long long
using namespace std;

const int MAXN = (int)2e5 + 5;
const int INF = 1e18;

int pos[MAXN], p[MAXN];
vector <pii> g[MAXN];

int n, m;

bool in(int pos) {
	return 0 <= pos && pos < n;
}

void crt(int pos, int x) {
	if (x == 0) { // wtf
		return;
	}
	if (!in(pos)) {
		return;
	}
	int l = pos;
	while (l >= 0) {
		if (l != pos) {
			g[pos].pb({abs(pos - l) / x, l});
		}
		l -= x;
	}
	int r = pos;
	while (r < n) {
		if (r != pos) {
			g[pos].pb({abs(r - pos) / x, r});
		}
		r += x;
	}		
}

int dist[MAXN];

signed main() {
	fastInp;
	cin >> n >> m;
	for (int i = 0; i < m; i++) {
		cin >> pos[i] >> p[i];
		crt(pos[i], p[i]);
	}
	
	//for (int i = 1; i <= 1e5; i++) {
		//cerr << "ok" << endl;
	//}
	
	memset(dist, -1, sizeof(dist));
	dist[pos[0]] = 0;
	queue <pii> pq;
	pq.push({0, pos[0]});
	while (!pq.empty()) {
		int v = pq.front().sc;
		int cost = -pq.front().fr;
		pq.pop();
		if (cost > dist[v]) {
			continue;
		}
		for (auto el : g[v]) {
			int c = el.fr, to = el.sc;
			if (dist[to] == -1 || dist[to] > dist[v] + c) {
				dist[to] = dist[v] + c;
				pq.push({-dist[to], to});
			}
		}
	}
	if (in(pos[1])) {
		cout << dist[pos[1]] << endl;
	} else {
		cout << -1 << endl;
	}
}
/*
4 4
1 1
0 1
3 4
2 0
*/

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