Cod sursa(job #2110849)

Utilizator UWantMyNameGheorghe Vlad Camil UWantMyName Data 21 ianuarie 2018 14:12:09
Problema Algoritmul lui Dijkstra Scor 40
Compilator cpp Status done
Runda Arhiva educationala Marime 1.46 kb
#include <bits/stdc++.h>
#define in "dijkstra.in"
#define out "dijkstra.out"
#define N 50003
#define oo 20003
using namespace std;
ifstream fin(in);
ofstream fout(out);

int n,m;
vector <pair <int,int> > L[N];
bitset <N> viz;
int d[N];

void Read()
{
    int i,x,y,cost;

    fin >> n >> m;
    for (i = 1; i <= m; i++)
    {
        fin >> x >> y >> cost;
        L[x].push_back({y,cost});
    }
}

void Dijkstra()
{
    int i,pas,minim,k,cost;

    for (i = 1; i <= n; i++)
        d[i] = oo;

    d[1] = 0;
    for (pas = 1; pas < n; pas++)
    {
        minim = oo; /// distanta minima
        k = 0;      /// nodul de distanta minima

        /// caut minimul in d
        for (i = 1; i <= n; i++)
            if (d[i] < minim && viz[i] == 0)
            {
                minim = d[i];
                k = i;
            }

        /// vad daca totusi se poate ajunge
        if (minim == oo) return;

        viz[k] = 1;
        for (auto w : L[k])
        {
            i = w.first;
            cost = w.second;
            if (d[i] > d[k] + cost) d[i] = d[k] + cost;
            /// am actualizat distanta minima la ceilalti vecini
        }
    }
}

void Afis()
{
    int i;

    for (i = 2; i <= n; i++)
        if (d[i] == oo) fout << "0 ";
        else fout << d[i] << " ";
    fout << "\n";
}

int main()
{
    Read();
    Dijkstra();
    Afis();

    fin.close();
    fout.close();
    return 0;
}