Cod sursa(job #2576075)

Utilizator GPuiaPuia Gabriel Nicolae GPuia Data 6 martie 2020 17:10:00
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.64 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;
ifstream f("dijkstra.in");
ofstream g1("dijkstra.out");

const int NMAX=50005;
const int oo=(1 << 30);

int n,m;
int d[NMAX];
bool InCoada[NMAX];

vector < pair < int, int > > g[NMAX];

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

priority_queue < int , vector <int>, comparaDistante > Coada;

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

void afisare()
{
    for(int i=2;i<=n;i++)
    {
        if(d[i]!=oo)
        {
            g1<<d[i]<<" ";
        }
        else
            g1<<"0";
    }
}

void dijkstra(int nodstart)
{
    for(int i=1;i<=n;i++)
    {
        d[i]=oo;
    }
    d[nodstart]=0;
    Coada.push(nodstart);
    InCoada[nodstart]=true;
    while(!Coada.empty())
    {
        int nodcurent = Coada.top();
        Coada.pop();
        InCoada[nodcurent]=false;
        for(unsigned int i=0;i<g[nodcurent].size();i++)
        {
            int vecin = g[nodcurent][i].first;
            int cost = g[nodcurent][i].second;
            if(d[nodcurent]+cost<d[vecin])
            {
                d[vecin]=d[nodcurent]+cost;
                if(InCoada[vecin]==false)
                {
                    Coada.push(vecin);
                    InCoada[vecin]=true;
                }
            }
        }
    }
}

int main()
{
    citeste();
    dijkstra(1);
    afisare();
    f.close();
    g1.close();
}