Cod sursa(job #2377040)

Utilizator vladsfStirbu Vlad Florin vladsf Data 8 martie 2019 21:07:40
Problema Algoritmul lui Dijkstra Scor 30
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.47 kb
#include <bits/stdc++.h>
#define nmax 50005
#define inf 5000

using namespace std;

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

int n,m,dist[nmax],incoada[nmax];

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

vector <pair <int,int> > G[nmax];

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

void citire()
{
    f>>n>>m;
    for (int i=1; i<=m; i++)
    {
        int x,y,c;
        f>>x>>y>>c;
        G[x].push_back({y,c});
    }
}

void afisare()
{
    for (int i=2; i<=n; i++)
    {
        if (dist[i]!=inf)
            g<<dist[i]<<" ";
        else
            g<<"0 ";
    }
}

void dijkstra(int start)
{
    for (int i=1; i<=n; i++)
        dist[i]=inf;
    dist[start]=0;
    coada.push(start);
    incoada[start]=1;
    while (!coada.empty())
    {
        int nx=coada.top();

        coada.pop();
        incoada[nx]=0;
        for (size_t i=0; i<G[nx].size(); i++)
        {
            int vecin= G[nx][i].first;
            int cost= G[nx][i].second;
            if (dist[nx]+cost<dist[vecin])
            {
                dist[vecin]=dist[nx]+cost;
                if (incoada[vecin]==0)
                    {coada.push(vecin);
                    incoada[vecin]=1;
                    }
            }
        }
    }
}

void hocus_pocus()
{
    citire();
    dijkstra(1);
    afisare();
}
int main()
{
    hocus_pocus();
    return 0;
}