Cod sursa(job #1981807)

Utilizator ilucianIlea Lucian ilucian Data 16 mai 2017 20:38:07
Problema Algoritmul lui Dijkstra Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 1.38 kb
#include <fstream>
#include <queue>
#include <vector>
#define INF 1000000000
using namespace std;

struct arc
{
    int dest,cost;
    arc()
    {

    }
    arc(int a, int b)
    {
        dest=a;
        cost=b;
    }
    bool operator <(const arc &a) const
    {
        if (cost<a.cost)
            return 1;
        return 0;
    }
};

ifstream fi("dijkstra.in");
ofstream fo("dijkstra.out");
int n,m,i;
int a,b,c;
vector <arc> V[50001];
vector <arc> :: iterator it;
int D[50001];
int S[50001];
priority_queue <arc> H;
arc curent,vecin;
int v;
int main()
{
    fi>>n>>m;
    for (i=1;i<=m;i++)
    {
        fi>>a>>b>>c;
        V[a].push_back(arc(b,c));
    }
    for (i=2;i<=n;i++)
        D[i]=INF;
    D[0]=0;
    for (i=2;i<=n;i++)
        S[i]=0;
    S[1]=1;
    H.push(arc(1,0));
    while (!H.empty())
    {
        curent=H.top();
        H.pop();
        v=curent.dest;
        for (it=V[v].begin();it!=V[v].end();it++)
        {
            vecin=(*it);
            if (D[v]+vecin.cost<D[vecin.dest])
            {
                D[vecin.dest]=D[v]+vecin.cost;
                H.push(arc(vecin.dest,D[vecin.dest]));
            }
        }
        S[v]=1;
    }
    for (i=2;i<=n;i++)
        if (S[i]==0)
            fo<<0<<" ";
        else
            fo<<D[i]<<" ";
    fi.close();
    fo.close();
    return 0;
}