Cod sursa(job #2838284)

Utilizator cdenisCovei Denis cdenis Data 23 ianuarie 2022 12:34:40
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.2 kb
#include <iostream>
#include <fstream>
#include <forward_list>
#include <queue>

using namespace std;

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

const int MAX=50005;
const int INF=2e9;
int n,m,a,b,c;
bool viz[MAX];
typedef pair < int, int > ipair;
forward_list < ipair > adj[MAX];
priority_queue < ipair, vector < ipair >, greater < ipair > > pq;
vector < int > dist (MAX, INF);

void dijkstra(int src)
{
    dist[src]=0;
    pq.push(make_pair(0,src));
    while(!pq.empty())
    {
        int u=pq.top().second;
        viz[u]=0;
        pq.pop();
        for(auto ngh : adj[u])
        {
            int v=ngh.first;
            int weight=ngh.second;
            if(dist[v]>dist[u]+weight)
            {
                dist[v]=dist[u]+weight;
                if(!viz[v])
                {
                    viz[v]=1;
                    pq.push(make_pair(dist[v],v));
                }
            }
        }
    }
}

int main()
{
    fin >> n >> m;
    for(;m;--m)
    {
        fin >> a >> b >> c;
        adj[a].push_front({b,c});
    }
    dijkstra(1);
    for(int i=2;i<=n;i++)
        fout << (dist[i]==INF?0:dist[i]) << " ";
    return 0;
}