Cod sursa(job #2681180)

Utilizator AlexTacuTacu Alexandru AlexTacu Data 5 decembrie 2020 09:36:23
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.47 kb
#include    <iostream>
#include    <fstream>
#include    <queue>
#include    <vector>

using namespace std;

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

const int Nmax=50005;
const int inf=(1<<30);

int n,m;
int Dist[Nmax];
int Viz[Nmax];

vector < pair <int,int> > V[Nmax];

struct compara
{
    bool operator()(int x,int y)
    {
        return V[x]>V[y];
    }
};

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

void citire()
{
    in>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int a,b,c;
        in>>a>>b>>c;
        V[a].push_back(make_pair(b,c));
    }
}

void dijkstra()
{
    for(int i=1;i<=n;i++)
        Dist[i]=inf;
    Dist[1]=0;
    q.push(1);
    Viz[1]=1;
    while(!q.empty())
    {
        int x=q.top();
        q.pop();
        Viz[x]=0;
        for(size_t i=0;i<V[x].size();i++)
        {
            int vecin=V[x][i].first;
            int cost=V[x][i].second;
            if(Dist[x]+cost<Dist[vecin])
            {
                Dist[vecin]=Dist[x]+cost;
                if(!Viz[vecin])
                    {
                        q.push(vecin);
                        Viz[vecin]=1;
                    }
            }
        }

    }
}

void afisare()
{
    for(int i=2;i<=n;i++)
    {
        if(Dist[i]!=inf)
            out<<Dist[i]<<' ';
        else
            out<<0<<' ';
    }
}

int main()
{
    citire();
    dijkstra();
    afisare();
    return 0;
}