Submission #1225636

#	Time	Username	Problem	Language	Result	Execution time	Memory
1225636		fermat	Jakarta Skyscrapers (APIO15_skyscraper)	C++20	100 / 100	132 ms	63160 KiB

skyscraper

#include <bits/stdc++.h>
 
#define mk make_pair
#define pb push_back
#define fr first
#define sc second
 
using namespace std;
 
const int N = 3e4 + 5;
 
int n, m, en, pos, p, d[N], st;
 
set <int, greater <int> > vec[N];

vector < vector <pair <int, int> > > g;
 
priority_queue < pair <int, int> > q;
 
int main() 
{
 cin >> n >> m;
 g.resize(n);
 for (int i = 1; i <= m; i++)
 {
  scanf("%d%d", &pos, &p);
  vec[pos].insert(p);
  if (i == 1)
   st = pos;
  if (i == 2)
   en = pos;
 }
 for (int i = 0; i < n; i++)
 {
  for (auto to : vec[i])
  {
   for (int j = i - to; j >= 0; j -= to)
   {
    g[i].pb(mk(j, (i - j) / to ) );
    if (vec[j].lower_bound(to) != vec[j].end() && *vec[j].lower_bound(to) == to)
     break;
   }
   for (int j = i + to; j < n; j += to)
   {
    g[i].pb(mk(j, (j - i) / to ) );
    if (vec[j].lower_bound(to) != vec[j].end() && *vec[j].lower_bound(to) == to)
     break;
   }
  }
 }
 memset(d, 0x3f3f3f3f, sizeof(d));
 d[st] = 0;
 q.push( mk( 0, st ) );
 
 while (!q.empty())
 {
  int v = q.top().sc, len = -q.top().fr;
  q.pop();
  if (d[v] < len) continue;
  
  for (auto to : g[v])
  {
   if (d[to.fr] > d[v] + to.sc)
   {
    d[to.fr] = d[v] + to.sc;
    q.push( mk( -d[to.fr], to.fr ) );
   }
  }
  
 }
 if (d[en] > 1e9)
  d[en] = -1;
 cout << d[en] << endl;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:26:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   26 |   scanf("%d%d", &pos, &p);
      |   ~~~~~^~~~~~~~~~~~~~~~~~

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