Cod sursa(job #2172149)

Utilizator raulrusu99Raul Rusu raulrusu99 Data 15 martie 2018 15:17:17
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 1.25 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream f("dijkstra.in");
ofstream g("dijkstra.out");
#define N_MAX 50005
#define inf (1<<31) - 1
int n, m, dist[N_MAX], viz[N_MAX];
vector <pair <int, int> > G[N_MAX];
///                   dist nod
priority_queue <pair <int, int> > pq;
void dijkstra(int start)
{
    int nod;
    for(int i = 1; i <= n; i++)
        dist[i] = inf;
    dist[start] = 0;
    pq.push({0,start});
    while(!pq.empty())
    {
        pair <int, int> _top = pq.top();
        pq.pop();
        nod = _top.second;
        if(viz[nod])
            continue;
        viz[nod] = 1;
        for(auto it:G[nod])
        {
            if(dist[it.first] > dist[nod] + it.second)
            {
                dist[it.first] = dist[nod] + it.second;
                pq.push({-dist[it.first], it.first});
            }
        }
    }
}
int main()
{
    f >> n >> m;
    int x, y, z;
    for(int i = 1; i <= m; i++)
    {
        f >> x >> y >> z;
        G[x].push_back({y,z});
        G[y].push_back({x,z});
    }
    dijkstra(1);
    for(int i = 2; i <= n; i++)
        if(dist[i] == inf) g << 0 << " ";
        else g << dist[i] << " ";
    return 0;
}