Cod sursa(job #522508)

Utilizator david_raucaRauca Ioan David david_rauca Data 15 ianuarie 2011 12:50:09
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.56 kb
#include<fstream>
#include<vector>
#include<algorithm>
using namespace std;

ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");

#define DIM 50001
#define INF 0x3f3f3f3f

int n, m;

vector<vector<pair<int, int> > > G;

bool s[DIM];

int sol[DIM];

void Read();
void Dijkstra();
void Write();

int main()
{
    Read();
    Dijkstra();
    Write();
    
    fin.close();
    fout.close();
    
    return 0;
}

void Read()
{
     fin >> n >> m;
     G.resize( n + 1 );
     int x, y, c;
     for( int i = 1; i <= m; ++i )
     {
          fin >> x >> y >> c;
          G[x].push_back( make_pair(y, c) );
          G[y].push_back( make_pair(x, c) );
     }
     
     for( int i = 1; i <= n; ++i )
          sol[i] = INF;
     
}

void Dijkstra()
{
     s[1] = true;
     sol[1] = 0;
     
     for( int i = 0; i < G[1].size(); ++i )
          sol[ G[1][i].first ] = G[1][i].second;
          
     int dmin, k;
       
     for( int p = 1; p < n; ++p )
     {
          dmin = INF;
          for( int i = 2; i <= n; ++i )
               if( !s[i] && dmin > sol[i] )
               {
                   dmin = sol[i];
                   k = i;
               }
          
          s[k] = true;
          
          for( int i = 0; i < G[k].size(); ++i )
               if( !s[ G[k][i].first ] && sol[ G[k][i].first ] > sol[k] + G[k][i].second )
                   sol[ G[k][i].first ] = sol[k] + G[k][i].second;
     }

}

void Write()
{
     for( int i = 2; i <= n; ++i )
          fout << sol[i] << ' '; 
}