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  1. //Not my code. Correcting the code given at https://d...content-available-to-author-only...f.com/questions/92244/what-is-the-wrong-in-this-code
  2.  
  3. #include<bits/stdc++.h>
  4. #define pii pair<int,int>
  5. #define infinity 99999999999
  6. using namespace std;
  7.  
  8.  long int n,m,u,v,w;
  9.  
  10.  
  11.  
  12.  
  13.  
  14.  
  15. long int dijkstra(int start, vector<pii>G[])
  16.  {
  17.      long int *dist = new long int[n+1];
  18.  
  19.      priority_queue<pii,vector<pii>,greater<pii> >q;
  20.  
  21.      for(int i=1; i<=n; i++)
  22.      {
  23.         dist[i]=infinity;
  24.      }
  25.  
  26.      q.push(pii(0,start));
  27.      dist[start]=0;
  28.  
  29.      while(!q.empty())
  30.      {
  31.         u=q.top().second;
  32.         q.pop();
  33.         for(int i=0; i<G[u].size();i++)
  34.         {
  35.             v=G[u][i].second;
  36.             w=G[u][i].first;
  37.             if(dist[u]+w<dist[v])
  38.             {
  39.                 dist[v]=dist[u]+w;
  40.                 q.push(pii(dist[v],v));
  41.             }
  42.         }
  43.      }
  44.  
  45.     long int mx  = 0;
  46.     for(int i=1; i<=n; i++)
  47.     {
  48.         mx = max(mx, dist[i]);
  49.     }
  50.     return mx;
  51.     free(dist);
  52.  }
  53.  
  54.  
  55.  
  56.  
  57.  
  58. int main()
  59. {
  60.      ios::sync_with_stdio(false);
  61.      cin>>n>>m;
  62.      vector<pii>G[n+1];
  63.      while(m--)
  64.      {
  65.         cin>>u>>v>>w;
  66.         G[u].push_back(pii(w,v));
  67.         G[v].push_back(pii(w,u));
  68.      }
  69.      long int ans=-infinity;
  70.      for(int i=1; i<=n; i++) //Now start from each i, and take maximum of all values mx returned by your function. 
  71.      {
  72.          int start = i;
  73.          ans=max(ans,dijkstra(start,G));
  74.      }
  75.      cout<<ans<<endl;
  76.      return 0;
  77.  
  78. }
Success #stdin #stdout 0s 15240KB
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stdin
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Standard input is empty
stdout
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-99999999999
https://ideone.com/ZWbXiZ
language:
C++14 (clang 8.0)
created:
8 years ago
visibility:
secret

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