Cod sursa(job #693724)

Utilizator andrei.finaruFinaru Andrei Emanuel andrei.finaru Data 27 februarie 2012 16:09:57
Problema Algoritmul lui Dijkstra Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 1.66 kb
#include <fstream>
#include <queue>

using namespace std;

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

int n,m,k,a,b,c,cost[50005],min;
char prez[50005];

struct nod
{
    int nr;
    int c;
    nod *urm;
} *v[50005],*p;

struct Comp
{
    bool operator() (int i, int j)
    {
        return cost[i]<cost[j];
    }
};

priority_queue<int, vector<int>, Comp> q;

void adaug(int a, int b, int c)
{
    nod *p;
    p=new nod;
    p->nr=b;
    p->c=c;
    p->urm=v[a];
    v[a]=p;
}

void afis()
{
    int i;
    for(i=2;i<=n;i++) g<<cost[i]<<' ';
    g<<'\n';
}

void dijkstra(int i)
{
    int x;
    prez[i]=1;
    q.push(i);
    while(!q.empty())
    {
        x=q.top();
        q.pop();
        p=v[x];
        prez[x]=0;
        while(p)
        {
            if((!cost[p->nr]||cost[p->nr]>cost[x]+p->c)&&!prez[p->nr])
            {
                cost[p->nr]=cost[x]+p->c;
                if(!prez[p->nr]) prez[p->nr]=1,q.push(p->nr);
            }
            p=p->urm;
        }
    }
   /* p=v[i];
    while(p) cost[p->nr]=p->c, p=p->urm;
    for(j=2;j<n;j++)
    {
        min=1;
	    while(viz[min]||!cost[min]) ++min;
		if(min>n) break;
		for(q=min+1;q<=n;q++)
			if(!viz[q]&&cost[q]&&cost[q]<cost[min]) min=q;
		viz[min]=1;
		p=v[min];
		while(p)
        {
            if((!cost[p->nr]||cost[p->nr]>cost[min]+p->c)&&!viz[p->nr]) cost[p->nr]=cost[min]+p->c;
            p=p->urm;
        }
    }*/
    afis();
}

int main()
{
    int i;
    f>>n>>m;
    for(i=1;i<=m;i++)
    {
        f>>a>>b>>c;
	    adaug(a,b,c);
    }
    dijkstra(1);
    f.close(); g.close();
    return 0;
}