Cod sursa(job #1922942)

Utilizator abccnuCamelia Zalum abccnu Data 10 martie 2017 19:44:07
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.45 kb
#include <fstream>
#include <vector>
#include <queue>
#include <fstream>
using namespace std;

ifstream cin ("dijkstra.in");
ofstream cout ("dijkstra.out");

const int NMAX = 50000 + 5;
const int INF = 999999999;

int N, M;
vector < pair< int , int > > gr[NMAX];
int d[NMAX];
bool vis[NMAX];

struct Elem
{
    int nod;
    int dist;

    Elem (int _nod = 0, int _dist = 0)
    {
        nod = _nod;
        dist = _dist;
    }

    bool operator< (const Elem & arg)const
    {
        return dist > arg.dist;
    }
};

priority_queue <Elem> q;

void Dijkstra (int x0)
{
    for (int i = 1; i <= N; ++i) d[i] = INF;

    d[x0] = 0;
    q.push(Elem(x0, 0));

    while (!q.empty())
    {
        int nod = q.top().nod;
        q.pop();

        if(vis[nod]) continue;

        vis[nod] = true;

        for (int i = 0; i < gr[nod].size(); ++i)
        {
            if (d[gr[nod][i].first] > d[nod] + gr[nod][i].second)
            {
                d[gr[nod][i].first] = d[nod] + gr[nod][i].second;
                q.push(Elem ( gr[nod][i].first, d[gr[nod][i].first]));
            }
        }
    }
}


int main()
{
    cin >> N >> M;
    int a, b, c;
    for (int i = 1; i <= M; ++i)
    {
        cin >> a >> b >> c;
        gr[a].push_back (make_pair (b,c));
    }
    Dijkstra(1);

    for (int i = 2; i <= N; ++i)
    {if (d[i] == INF) cout << 0 << " ";
    else
        cout << d[i] << " ";
    }
}