Cod sursa(job #1379223)

Utilizator roxana_97Soare Roxana Florentina roxana_97 Data 6 martie 2015 17:04:17
Problema Algoritmul lui Dijkstra Scor 80
Compilator cpp Status done
Runda Arhiva educationala Marime 1.35 kb
#include<fstream>
#include<vector>
#include<bitset>
#include<queue>
#define Nmax 500009
#define inf 2000000000
using namespace std;

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

int x,n,m,ante[Nmax],d[Nmax],S,F;
struct muchie
{
    int y,c;
}aux;
vector<muchie> G[Nmax];
struct cmp
{
    bool operator()(int x, int y)
    {
        return d[x]>d[y];
    }
};
priority_queue<int, vector<int>,cmp > pq;

 void Dijkstra(int S)
{
    for(int i=1;i<=n;i++) ante[i]=d[i]=inf;
    ante[S]=d[S]=0;
    pq.push(S);
    while(!pq.empty())
    {
        int node=pq.top();
        pq.pop();
        for(vector<muchie> :: iterator it=G[node].begin();it!=G[node].end();it++)
            if(d[node]+it->c <d[it->y])
            {
                d[it->y]=d[node]+it->c;
                ante[it->y]=node;
                pq.push(it->y);
            }
    }
    for(int i=1;i<=n;i++)
        if(d[i]==inf) d[i]=ante[i]=0;
}

/*void Rebuild(int node)
{
    if(node==S)
    {
        g<<S<<' ';
        return;
    }
    Rebuild(ante[node]);
    g<<node<<' ';
}*/


int main()
{
    f>>n>>m;
    S=1;
    F=n;
    for(int i=1;i<=m;i++)
    {
        f>>x>>aux.y>>aux.c;
        G[x].push_back(aux);
    }
    Dijkstra(S);
    for(int i=2;i<=n;i++) g<<d[i]<<' ';
    g<<'\n';
    f.close();g.close();
    return 0;
}