Cod sursa(job #1171403)

Utilizator rogoz.bogdanRogoz Bogdan rogoz.bogdan Data 15 aprilie 2014 18:02:22
Problema Algoritmul lui Dijkstra Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 1.52 kb
#include <fstream>
#include <vector>
#include <queue>
#include <map>
#define MX 50001
using namespace std;

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

int d[MX];

struct vecin
{
    int j,c;
};

struct comp
{
    bool operator() (int a, int b)
    {
        return d[a] > d[b];
    }
};

int n,m;
int viz[MX];
multimap<int, vecin> v;
priority_queue<int, vector<int>, comp> p;

void citire()
{
    int i,a,b,c;
    vecin x;
    pair<int, vecin> y;
    fin>>n>>m;
    for(i=1; i<=m; i++)
    {
        fin>>a>>b>>c;
        x.j = b;
        x.c = c;
        y.first = a;
        y.second = x;
        v.insert(y);
    }
}

void dijkstra()
{
    vecin x;
    int i,u,r,nr;
    multimap<int, vecin>::iterator it;

    p.push(1);
    viz[1] = 1;
    while(!p.empty())
    {
        u = p.top();
        p.pop();
        nr = v.count(u);
        while(nr)
        {
            //
            it = v.find(u);
            //fout<<it->first<<' ';
            x = it->second;
            r = d[u] + x.c;
            if(viz[x.j] == 0)
            {
                viz[x.j] = 1;
                d[x.j] = r;
                p.push(x.j);
            }
            else
            if(r < d[x.j])
            {
                d[x.j] = r;
            }

            v.erase(it);
            nr--;
        }
    }
}

int main()
{
    int i;
    citire();
    dijkstra();
    for(i=2; i<=n; i++) fout<<d[i]<<' ';

    fin.close(); fout.close();
    return 0;
}