Submission #472581

#	Time	Username	Problem	Language	Result	Execution time	Memory
472581		ZaZo_	Toll (BOI17_toll)	C++14	25 / 100	3061 ms	7064 KiB

toll

#include <bits/stdc++.h>
#define ZAZO ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define int long long
using namespace std;
vector<pair<int,int>>edges[50001];
int k , n , m , o ;
int dist[50001];
void prepare()
{
  for(int i = 0 ; i < n+1 ; i ++) dist[i]=1e15;
}
void djk(int s , int e)
{
  priority_queue<pair<int,int>>pq;
  dist[s]=0;
  pq.push({0,s});
  while(!pq.empty())
  {
    int c = -pq.top().first , u = pq.top().second;
    pq.pop();
    for(int i = 0 ; i < edges[u].size() ; i++)
    {
      if(dist[edges[u][i].first] > dist[u] + edges[u][i].second)
      {
        dist[edges[u][i].first] = dist[u] + edges[u][i].second;
        pq.push({-dist[edges[u][i].first],edges[u][i].first});
      }
    }
  }
}
int32_t main() {
  ZAZO
  cin >> k >> n >> m >> o ;
  int pref[50011];
  for(int i = 0 ; i <= 50001 ; i ++) pref[i]=-1e9;
  for(int i = 0 ; i < m ; i ++)
  {
    int a , b , t;
    cin >> a >> b >> t;
    edges[a].push_back({b,t});
    pref[b]=t;
  }
  if(k!=1){
  vector<pair<int,pair<int,int>>>v;
  for(int i = 0 ; i < o ; i ++)
  {
    int a , b;
    cin >> a >> b;
    v.push_back({i,{min(a,b),max(a,b)}});
  }
  sort(v.begin(),v.end());
  int ans[o];
  for(int i = 0 ; i < o ; i ++) ans[i]=-1;
  for(int i = 0 ; i < v.size() ; i++)
  {
    if(i && v[i].second.first == v[i-1].second.first)
    {
      if(dist[v[i].second.second] != 1e15) ans[v[i].first]=dist[v[i].second.second];
    }
    else
    {
      prepare();
      djk(v[i].second.first , v[i].second.second);
      if(dist[v[i].second.second]!=1e15)
        ans[v[i].first] = dist[v[i].second.second];
    }
  }
  for(int i = 0 ; i < o ; i++)
  cout<<ans[i]<<endl;
  }
  else
  {
      for(int i = 1  ; i <= 50001 ; i++)
      {
        pref[i]+=pref[i-1];
      }
      for(int i = 0 ; i < o ; i ++)
      {
        int a , b;
        cin>>a>>b;
        if(pref[b]-pref[a]<=0) cout<<"-1"<<endl;
        else cout<<pref[b]-pref[a]<<endl;
      }
  }
}

Compilation message (stderr)

toll.cpp: In function 'void djk(long long int, long long int)':
toll.cpp:21:23: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |     for(int i = 0 ; i < edges[u].size() ; i++)
      |                     ~~^~~~~~~~~~~~~~~~~
toll.cpp:19:9: warning: unused variable 'c' [-Wunused-variable]
   19 |     int c = -pq.top().first , u = pq.top().second;
      |         ^
toll.cpp: In function 'int32_t main()':
toll.cpp:54:21: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, std::pair<long long int, long long int> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |   for(int i = 0 ; i < v.size() ; i++)
      |                   ~~^~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 10 / 10
• Subtask 3: 8 / 8
• Subtask 4: 0 / 31
• Subtask 5: 0 / 44