Submission #66648

#	Time	Username	Problem	Language	Result	Execution time	Memory
66648		tincamatei	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	57 / 100	1097 ms	63800 KiB

skyscraper

#include <bits/stdc++.h>

using namespace std;

const int MAX_N = 30000;

vector<pair<int, int> > graph[MAX_N];
map<pair<int, int>, bool> doges;

int dist[MAX_N];

int dijkstra(int n, int src, int dest) {
  priority_queue<pair<int, int>, vector<pair<int, int> >, greater<pair<int, int> > > pq;
  memset(dist, 0x3f3f3f3f, sizeof(dist));
  dist[src] = 0;
  pq.push(make_pair(0, src));
  while(!pq.empty()) {
    int nod = pq.top().second, distNod = pq.top().first;
    pq.pop();

    if(dist[nod] == distNod) {
      for(auto it: graph[nod])
      if(distNod + it.second < dist[it.first]) {
        dist[it.first] = distNod + it.second;
        pq.push(make_pair(dist[it.first], it.first));
      }
    }
  }

  if(dist[dest] == 0x3f3f3f3f)
    return -1;
  else
    return dist[dest];
}

int main() {
  int n, m, b, p, src, dest;
  scanf("%d%d", &n, &m);

  for(int i = 0; i < m; ++i) {
    scanf("%d%d", &b, &p);
    if(i == 0)
      src = b;
    if(i == 1)
      dest = b;
    doges[make_pair(b, p)] = true;
  }

  for(auto it: doges) {
    pair<int, int> doge = it.first;
    if(it.second) {
      int poz = doge.first - doge.second, cost = 1;
      bool foundSimilar = false;
      while(poz >= 0 && !foundSimilar) {
        graph[doge.first].push_back(make_pair(poz, cost++));
        if(doges[make_pair(poz, doge.second)])
          foundSimilar = true;
        poz -= doge.second;
      }

      poz = doge.first + doge.second, cost = 1;
      foundSimilar = false;
      while(poz < n && !foundSimilar) {
        graph[doge.first].push_back(make_pair(poz, cost++));
        if(doges[make_pair(poz, doge.second)])
          foundSimilar = true;
        poz += doge.second;
      }
    }
  }

  printf("%d", dijkstra(n, src, dest));
  return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:38:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &n, &m);
   ~~~~~^~~~~~~~~~~~~~~~
skyscraper.cpp:41:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &b, &p);
     ~~~~~^~~~~~~~~~~~~~~~
skyscraper.cpp:72:9: warning: 'dest' may be used uninitialized in this function [-Wmaybe-uninitialized]
   printf("%d", dijkstra(n, src, dest));
   ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:72:9: warning: 'src' may be used uninitialized in this function [-Wmaybe-uninitialized]

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