Submission #483871

#	Time	Username	Problem	Language	Result	Execution time	Memory
483871		Sohsoh84	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	866 ms	48056 KiB

skyscraper

//: // ////: ///  / : //// / :
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<ll, pll> plll;

#define all(x)			(x).begin(),(x).end()
#define X			first
#define Y			second
#define sep			' '
#define endl			'\n'
#define debug(x)		cerr << #x << ": " <<  x << endl;

const ll MAXN = 30000 + 10;
const ll SQ = 170;
const ll INF = 1e18;

vector<int> vec[MAXN];
ll dist[MAXN][SQ], B[MAXN], P[MAXN], n, m;
bool F[MAXN][SQ];
priority_queue<plll, vector<plll>, greater<plll>> pq;

inline void update(int v, int p, int d) {
	if (d < dist[v][p]) {
		dist[v][p] = d;
		pq.push({d, {v, p}});
	}
}

inline void dijkstra() {
	while (!pq.empty()) {
		int v = pq.top().Y.X, p = pq.top().Y.Y, d = pq.top().X;
		pq.pop();
		if (d != dist[v][p]) continue;
		
		if (p) {
			update(v, 0, d);
			if (v + p < n) update(v + p, p, d + 1);
			if (v - p >= 0) update(v - p, p, d + 1);
		} else {
			for (int i = 1; i < SQ; i++)
				if (F[v][i])
					update(v, i, d);
			for (int e : vec[v]) {
				int ind = 0;
				for (int u = v + e; u < n; u += e)
					ind++, update(u, 0, d + ind); //
			
				ind = 0;
				for (int u = v - e; u >= 0; u -= e)
					ind++, update(u, 0, d + ind); //
			}
		}
	}
}

int main() {
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	cin >> n >> m;
	for (int i = 0; i < m; i++) {
		cin >> B[i] >> P[i];
		if (P[i] >= SQ) vec[B[i]].push_back(P[i]);
		else F[B[i]][P[i]] = true;
	}

	for (int i = 0; i < n; i++)
		memset(dist[i], 63, sizeof dist[i]);

	pq.push({0, {B[0], 0}});
	dist[B[0]][0] = 0;
	dijkstra();

	cout << (dist[B[1]][0] > INF ? -1 : dist[B[1]][0]) << endl;
	return 0;
}

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