Submission #456450

#	Time	Username	Problem	Language	Result	Execution time	Memory
456450		elgamalsalman	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	0 / 100	1 ms	332 KiB

skyscraper

#include <bits/stdc++.h>

using namespace std;

#define fi first
#define se second
#define ww first
#define vv second

typedef pair<int, int> ii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<vi> vvi;
typedef vector<vii> vvii;

int N, M, b[30'050], p[30'050], sssp[30'050];
vvi dogesAt;
vvii adj;

void dijkstra(int source) {
  memset(sssp, -1, sizeof sssp);
  priority_queue<ii> pq;
  pq.push({0, source});
  while (!pq.empty()) {
    ii u = pq.top(); pq.pop();
    u.ww = -u.ww;
    //cerr << "// pq.top() : {" << u.fi << ", " << u.se << "}\n";
    if (sssp[u.vv] != -1 && sssp[u.vv] <= u.ww) continue;
    sssp[u.vv] = u.ww;
    for (ii v : adj[u.vv]) {
      int newDis = u.ww + v.ww;
      if (sssp[v.vv] == -1 || sssp[v.vv] > newDis) {
	pq.push({-newDis, v.vv});
      }
    }
  }
}

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);

  cin >> N >> M;
  dogesAt.assign(N, vi());
  adj.assign(M, vii());
  for (int i = 0; i < M; i++) {
    cin >> b[i] >> p[i];
    dogesAt[b[i]].push_back(i);
  }

  for (int i = 0; i < M; i++) {
    for (int j = b[i] + p[i], stepCount = 1; j < N; j += p[i], stepCount++) {
      for (int d : dogesAt[j]) adj[i].push_back({stepCount, d});
    }

    for (int j = b[i] - p[i], stepCount = 1; j >= 0; j -= p[i], stepCount++) {
      for (int d : dogesAt[j]) adj[i].push_back({stepCount, d});
    }
  }

  //cerr << "// adj:-\n";
  //for (int u = 0; u < M; u++) {
  //  cerr << "// " << u << " :";
  //  for (ii v : adj[u]) cerr << " {" << v.fi << ", " << v.se << "}";
  //  cerr << '\n';
  //}
  //cerr << '\n';

  dijkstra(0);

  //cerr << "// sssp :";
  //for (int i = 0; i < M; i++) cerr << ' ' << sssp[i];
  //cerr << '\n';

  cout << sssp[1] << '\n';
}

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