Cod sursa(job #2516087)

Utilizator cyg_Alex_codegicianBarbu Alexandru cyg_Alex_codegician Data 30 decembrie 2019 12:36:04
Problema Algoritmul lui Dijkstra Scor 50
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.54 kb
#include <fstream>
#include <queue>
#include <vector>
using namespace std;
ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");
const int NMAX=50005,inf=1<<30;
int n,m;
int distanta[NMAX];
bool inCoada[NMAX];
vector < pair<int, int> > muchii[NMAX];
struct compara
{
    bool operator()(int x,int y)
    {
        return distanta[x]<distanta[y];
    }
};
priority_queue < int, vector <int>, compara > q;
void citire()
{
    fin >> n >> m;
    for (int i=1;i<=m;i++)
    {
        int x,y,z;
        fin >> x >> y >> z;
        muchii[x].push_back(make_pair(y,z));
    }
}
void dijkstra(int nodStart)
{
    for (int i=1;i<=n;i++)
    {
        distanta[i]=inf;
    }
    q.push(nodStart);
    inCoada[nodStart]=true;
    distanta[nodStart]=0;
    while (!q.empty())
    {
        int nodCurent=q.top();
        q.pop();
        inCoada[nodCurent]=false;
        for (int i=0;i<muchii[nodCurent].size();i++)
        {
            int vecin=muchii[nodCurent][i].first;
            int cost=muchii[nodCurent][i].second;
            if (distanta[nodCurent]+cost<distanta[vecin])
            {
                distanta[vecin]=distanta[nodCurent]+cost;
                if (inCoada[vecin]==false)
                {
                    q.push(vecin);
                    inCoada[vecin]=true;
                }
            }
        }
    }
}
void afisare()
{
    for (int i=2;i<=n;i++)
    {
        if (distanta[i]!=inf)
            fout << distanta[i];
        else
            fout << 0;
        fout << " ";
    }
}
int main()
{
    citire();
    dijkstra(1);
    afisare();
}