Submission #472506

#	Time	Username	Problem	Language	Result	Execution time	Memory
472506		ZaZo_	Toll (BOI17_toll)	C++14	10 / 100	83 ms	4356 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],vis[50001]={0};
void prepare()
{
  for(int i = 0 ; i < n+1 ; i ++) dist[i]=INT_MAX;
}
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;
    vis[u]=1;
    pq.pop();
    for(int i = 0 ; i < edges[u].size() ; i++)
    {
      if(!vis[edges[u][i].first]&&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 ;
  for(int i = 0 ; i < m ; i ++)
  {
    int a , b , t;
    cin >> a >> b >> t;
    edges[a].push_back({b,t});
  }
  vector<pair<int,pair<int,int>>>v;
  prepare();
  djk(0,n);
  for(int i = 0 ; i < o ; i ++)
  {
    int a , b;
    cin >> a >> b;
    if(!vis[a])
    {
      prepare();
      memset(vis,0,sizeof vis);
      djk(a,n);
    }
    if(dist[b]!=INT_MAX) cout<<dist[b]<<endl;
    else cout<<"-1"<<endl;
  }
}

Compilation message (stderr)

toll.cpp: In function 'void djk(int, int)':
toll.cpp:22:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |     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;
      |         ^

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