Cod sursa(job #1554552)

Utilizator narcischitescuNarcis Chitescu narcischitescu Data 21 decembrie 2015 14:24:20
Problema Algoritmul lui Dijkstra Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 1.33 kb
#include <iostream>
#include <fstream>
#include <cstring>
#include <queue>
#include <vector>
#include <algorithm>

#define pb push_back
#define mp make_pair

#define MAX 50001
#define INF 0x3f3f3f3f

using namespace std;

ifstream f("dijkstra.in");
ofstream g("dijkstra.out");

vector < pair < int , int > > G[MAX] ;
vector < pair < int , int > >::iterator j;
int  USED[MAX] ;
int  D[MAX];
queue < int > Q;

int n,m,x,y,z,start;

void bellman_ford( int i )
{
    memset( D , INF , sizeof D);
    D[i] = 0;
    USED[i] = true;
    Q.push(i);
    int nod;

    while(!Q.empty())
    {
        nod = Q.front();
        Q.pop();
        USED[nod] = false;
        for ( j = G[nod].begin(); j != G[nod].end(); j++ )
        {
            if (  D[ (*j).first ] > D[nod] + (*j).second )
            {
                D[ (*j).first ] = D[nod] + (*j).second;
                if( !USED[ (*j).first ] )
                {
                    Q.push( (*j).first);
                    USED[ (*j).first ] = true;
                }
            }
        }
    }
}

int main()
{
    f >> n >> m;

    for ( ; m-- ;  )
    {
        f >> x >> y >> z;
        G[x].pb(mp (y,z) );
    }

    start = 1;

    bellman_ford(start);

    for (int i = 2; i <= n ; ++i )
        g << D[i] << " " ;


    return 0;
}